Information Systems for Business and Beyond
David T. Bourgeois, Ph.D.
Information Systems for Business and Beyond © 2014 David T. Bourgeois, is licensed under a Creative Commons Attribution (CC BY) license made possible by funding from The Saylor Foundation's Open Textbook Challenge in order to be incorporated into Saylor.org's collection of open courses available at http://www.saylor.org. Full license terms may be viewed at: http://creativecommons.org/licenses/by/3.0/legalcode
Welcome to Information Systems for Business and Beyond. In this book, you will be introduced to the concept of information systems, their use in business, and the larger impact they are having on our world.
This book is written as an introductory text, meant for those with little or no experience with computers or information systems. While sometimes the descriptions can get a little bit technical, every effort has been made to convey the information essential to understanding a topic while not getting bogged down in detailed terminology or esoteric discussions.
The text is organized around thirteen chapters divided into three major parts, as follows:
• Part 1: What Is an Information System?
Chapter 1: What Is an Information System? – This chapter provides an overview of information systems, including the history of how we got where we are today.
Chapter 2: Hardware – We discuss information systems hardware and how it works. You will look at different computer parts and learn how they interact.
Chapter 3: Software – Without software, hardware is useless. In this chapter, we discuss software and the role it plays in an organization.
Chapter 4: Data and Databases – This chapter explores how organizations use information systems to turn data into information that can then be used for competitive advantage. Special attention is paid to the role of databases.
Chapter 5: Networking and Communication – Today’s computers are expected to also be communication devices. In this chapter we review the history of networking, how the Internet works, and the use of networks in organizations today.
Chapter 6: Information Systems Security – We discuss the information security triad of confidentiality, integrity, and availability. We will review different security technologies, and the chapter concludes with a primer on personal information security.
• Part 2: Information Systems for Strategic Advantage
Chapter 7: Does IT Matter? – This chapter examines the impact that information systems have on an organization. Can IT give a company a competitive advantage? We will discuss seminal works by Brynjolfsson, Carr, and Porter as they relate to IT and competitive advantage.
Chapter 8: Business Processes – Business processes are the essence of what a business does, and information systems play an important role in making them work. This chapter will discuss business process management, business process reengineering, and ERP systems.
Chapter 9: The People in Information Systems – This chapter will provide an overview of the different types of people involved in information systems. This includes people who create information systems, those who operate and administer information systems, those who manage information systems, and those who use information systems.
Chapter 10: Information Systems Development – How are information systems created? This chapter will review the concept of programming, look at different methods of software development, review website and mobile application development, discuss end- user computing, and look at the “build vs. buy” decision that many companies face.
• Part 3: Information Systems beyond the Organization
Chapter 11: Globalization and the Digital Divide – The rapid rise of the Internet has made it easier than ever to do business worldwide. This chapter will look at the impact that the Internet is having on the globalization of business and the issues that firms must face because of it. It will also cover the concept of the digital divide and some of the steps being taken to alleviate it.
Chapter 12: The Ethical and Legal Implications of Information Systems – The rapid changes in information and communication technology in the past few decades have brought a broad array of new capabilities and powers to governments, organizations, and individuals alike. This chapter will discuss the effects that these new capabilities have had and the legal and regulatory changes that have been put in place in response.
Chapter 13: Future Trends in Information Systems – This final chapter will present an overview of some of the new technologies that are on the horizon. From wearable technology to 3-D printing, this chapter will provide a look forward to what the next few years will bring.
For the Student
Each chapter in this text begins with a list of the relevant learning objectives and ends with a chapter summary. Following the summary is a list of study questions that highlight key topics in the chapter. In order to get the best learning experience, you would be wise to begin by reading both the learning objectives and the summary and then reviewing the questions at the end of the chapter.
For the Instructor
Learning objectives can be found at the beginning of each chapter. Of course, all chapters are recommended for use in an introductory information systems course. However, for courses on a shorter calendar or courses using additional textbooks, a review of the learning objectives will help determine which chapters can be omitted.
At the end of each chapter, there is a set of study questions and exercises (except for chapter 1, which only offers study questions). The study questions can be assigned to help focus students’ reading on the learning objectives. The exercises are meant to be a more in-depth, experiential way for students to learn chapter topics. It is recommended that you review any exercise before assigning it, adding any detail needed (such as length, due date) to complete the assignment.
Upon successful completion of this chapter, you will be able to:
• define what an information system is by identifying its major components;
• describe the basic history of information systems; and
• describe the basic argument behind the article “Does IT Matter?” by Nicholas Carr.
If you are reading this, you are most likely taking a course in information systems, but do you even know what the course is going to cover? When you tell your friends or your family that you are taking a course in information systems, can you explain what it is about? For the past several years, I have taught an Introduction to Information Systems course. The first day of class I ask my students to tell me what they think an information system is. I generally get answers such as “computers,” “databases,” or “Excel.” These are good answers, but definitely incomplete ones. The study of information systems goes far beyond understanding some technologies. Let’s begin our study by defining information systems.
Defining Information Systems
Almost all programs in business require students to take a course in something called information systems. But what exactly does that term mean? Let’s take a look at some of the more popular definitions, first from Wikipedia and then from a couple of textbooks:
• “Information systems (IS) is the study of complementary networks of hardware and software that people and organizations use to collect, filter, process, create, and distribute data.”1
• “Information systems are combinations of hardware, software, and telecommunications networks that people build and use to collect, create, and distribute useful data, typically in organizational settings.”2
• “Information systems are interrelated components working together to collect, process, store, and disseminate information to support decision making, coordination, control, analysis, and viualization in an organization.”3
1. Wikipedia entry on "Information Systems," as displayed on August 19, 2012. Wikipedia: The Free Encyclopedia. San Francisco: Wikimedia Foundation. http://en.wikipedia.org/wiki/Information_systems_(discipline).
2. Excerpted from Information Systems Today - Managing in the Digital World, fourth edition. Prentice-Hall, 2010.
3. Excerpted from Management Information Systems, twelfth edition, Prentice-Hall, 2012.
As you can see, these definitions focus on two different ways of describing information systems: the components that make up an information system and the role that those components play in an organization. Let’s take a look at each of these.
The Components of Information Systems
As I stated earlier, I spend the first day of my information systems class discussing exactly what the term means. Many students understand that an information system has something to do with databases or spreadsheets. Others mention computers and e-commerce. And they are all right, at least in part: information systems are made up of different components that work together to provide value to an organization.
The first way I describe information systems to students is to tell them that they are made up of five components: hardware, software, data, people, and process. The first three, fitting under the category technology, are generally what most students think of when asked to define information systems. But the last two, people and process, are really what separate the idea of information systems from more technical fields, such as computer science. In order to fully understand information systems, students must understand how all of these components work together to bring value to an organization.
Technology can be thought of as the application of scientific knowledge for practical purposes. From the invention of the wheel to the harnessing of electricity for artificial lighting, technology is a part of our lives in so many ways that we tend to take it for granted. As discussed before, the first three components of information systems – hardware, software, and data – all fall under the category of technology. Each of these will get its own chapter and a much lengthier discussion, but we will take a moment here to introduce them so we can get a full understanding of what an information system is.
Information systems hardware is the part of an information system you can touch – the physical components of the technology. Computers, keyboards, disk drives, iPads, and flash drives are all examples of information systems hardware. We will spend some time going over these components and how they all work together in chapter 2.
Software is a set of instructions that tells the hardware what to do. Software is not tangible – it cannot be touched. When programmers create software programs, what they are really doing is simply typing out lists of instructions that tell the hardware what to do. There are several categories of software, with the two main categories being operating-system software, which makes the hardware usable, and application software, which does something useful. Examples of operating systems include Microsoft Windows on a personal computer and Google’s Android on a mobile phone. Examples of application software are Microsoft Excel and Angry Birds. Software will be explored more thoroughly in chapter 3.
The third component is data. You can think of data as a collection of facts. For example, your street address, the city you live in, and your phone number are all pieces of data. Like software, data is also intangible. By themselves, pieces of data are not really very useful. But aggregated, indexed, and organized together into a database, data can become a powerful tool for businesses. In fact, all of the definitions presented at the beginning of this chapter focused on how information systems manage data. Organizations collect all kinds of data and use it to make decisions. These decisions can then be analyzed as to their effectiveness and the organization can be improved. Chapter 4 will focus on data and databases, and their uses in organizations.
Networking Communication: A Fourth Technology Piece?
Besides the components of hardware, software, and data, which have long been considered the core technology of information systems, it has been suggested that one other component should be added: communication. An information system can exist without the ability to communicate – the first personal computers were stand-alone machines that did not access the Internet. However, in today’s hyper-connected world, it is an extremely rare computer that does not connect to another device or to a network. Technically, the networking communication component is made up of hardware and software, but it is such a core feature of today’s information systems that it has become its own category. We will be covering networking in chapter 5.
When thinking about information systems, it is easy to get focused on the technology components and forget that we must look beyond these tools to fully understand how they integrate into an organization. A focus on the people involved in information systems is the next step. From the front-line help-desk workers, to systems analysts, to programmers, all the way up to the chief information officer (CIO), the people involved with information systems are an essential element that must not be overlooked. The people component will be covered in chapter 9.
The last component of information systems is process. A process is a series of steps undertaken to achieve a desired outcome or goal. Information systems are becoming more and more integrated with organizational processes, bringing more productivity and better control to those processes. But simply automating activities using technology is not enough – businesses looking to effectively utilize information systems do more. Using technology to manage and improve processes, both within a company and externally with suppliers and customers, is the ultimate goal. Technology buzzwords such as “business process reengineering,” “business process management,” and “enterprise resource planning” all have to do with the continued improvement of these business procedures and the integration of technology with them. Businesses hoping to gain an advantage over their competitors are highly focused on this component of information systems. We will discuss processes in chapter 8.
The Role of Information Systems
Now that we have explored the different components of information systems, we need to turn our attention to the role that information systems play in an organization. So far we have looked at what the components of an information system are, but what do these components actually do for an organization? From our definitions above, we see that these components collect, store, organize, and distribute data throughout the organization. In fact, we might say that one of the roles of information systems is to take data and turn it into information, and then transform that into organizational knowledge. As technology has developed, this role has evolved into the backbone of the organization. To get a full appreciation of the role information systems play, we will review how they have changed over the years.
The Mainframe Era
From the late 1950s through the 1960s, computers were seen as a way to more efficiently do calculations. These first business computers were room-sized monsters, with several refrigerator-sized machines linked together. The primary work of these devices was to organize and store large volumes of information that were tedious to manage by hand. Only large businesses, universities, and government agencies could afford them, and they took a crew of specialized personnel and specialized facilities to maintain. These devices served dozens to hundreds of users at a time through a process called time-sharing. Typical functions included scientific calculations and accounting, under the broader umbrella of “data processing.”
IBM 704 Mainframe (Copyright: Lawrence Livermore
In the late 1960s, the Manufacturing Resources Planning (MRP) systems were introduced. This software, running on a mainframe computer, gave companies the ability to manage the manufacturing process, making it more efficient. From tracking inventory to creating bills of materials to scheduling production, the MRP systems (and later the MRP II systems) gave more businesses a reason to want to integrate computing into their processes. IBM became the dominant mainframe company. Nicknamed “Big Blue,” the company became synonymous with business computing. Continued improvement in software and the availability of cheaper hardware eventually brought mainframe computers (and their little sibling, the minicomputer) into most large businesses.
Registered trademark of International Business Machines
The PC Revolution
In 1975, the first microcomputer was announced on the cover of Popular Mechanics: the Altair 8800. Its immediate popularity sparked the imagination of entrepreneurs everywhere, and there were quickly dozens of companies making these “personal computers.” Though at first just a niche product for computer hobbyists, improvements in usability and the availability of practical software led to growing sales. The most prominent of these early personal computer makers was a little company known as Apple Computer, headed by Steve Jobs and Steve Wozniak, with the hugely successful “Apple II.” Not wanting to be left out of the revolution, in 1981 IBM (teaming with a little company called Microsoft for their operating-system software) hurriedly released their own version of the personal computer, simply called the “PC.” Businesses, who had used IBM mainframes for years to run their businesses, finally had the permission they needed to bring personal computers into their companies, and the IBM PC took off. The IBM PC was named Time magazine’s “Man of the Year” for 1982.
Because of the IBM PC’s open architecture, it was easy for other companies to copy, or “clone” it. During the 1980s, many new computer companies sprang up, offering less expensive versions of the PC. This drove prices down and spurred innovation. Microsoft developed its Windows operating system and made the PC even easier to use. Common uses for the PC during this period included word processing, spreadsheets, and databases. These early PCs were not connected to any sort of network; for the most part they stood alone as islands of innovation within the larger organization.
In the mid-1980s, businesses began to see the need to connect their computers together as a way to collaborate and share resources. This networking architecture was referred to as “client-server” because users would log in to the local area network (LAN) from their PC (the “client”) by connecting to a powerful computer called a “server,” which would then grant them rights to different resources on the network (such as shared file areas and a printer). Software companies began developing applications that allowed multiple users to access the same data at the same time. This evolved into software applications for communicating, with the first real popular use of electronic mail appearing at this time.
This networking and data sharing all stayed within the confines of each business, for the most part. While there was sharing of electronic data between companies, this was a very specialized function. Computers were now seen as tools to collaborate internally, within an organization. In fact, these networks of computers were becoming so powerful that they were replacing many of the functions previously performed by the larger mainframe computers at a fraction of the cost.
Registered trademark of SAP
It was during this era that the first Enterprise Resource Planning (ERP) systems were developed and run on the client-server architecture. An ERP system is a software application with a centralized database that can be used to run a company’s entire business. With separate modules for accounting, finance, inventory, human resources, and many, many more, ERP systems, with Germany’s SAP leading the way, represented the state of the art in information systems integration. We will discuss ERP systems as part of the chapter on process (chapter 9).
The World Wide Web and E-Commerce
First invented in 1969, the Internet was confined to use by universities, government agencies, and researchers for many years. Its rather arcane commands and user applications made it unsuitable for mainstream use in business. One exception to this was the ability to expand electronic mail outside the confines of a single organization. While the first e-mail messages on the Internet were sent in the early
1970s, companies who wanted to expand their LAN-based e-mail started hooking up to the Internet in the
1980s. Companies began connecting their internal networks to the Internet in order to allow communication between their employees and employees at other companies. It was with these early Internet connections that the computer truly began to evolve from a computational device to a communications device.
In 1989, Tim Berners-Lee developed a simpler way for researchers to share information over the network at CERN laboratories, a concept he called the World Wide Web.4 This invention became the launching point of the growth of the Internet as a way for businesses to share information about themselves.
As web browsers and Internet connections became the norm, companies rushed to grab domain names and create websites.
In 1991, the National Science Foundation, which governed how the Internet was used, lifted restrictions on its commercial use. The year 1994 saw the establishment of both eBay and Amazon.com, two true pioneers in the use of the new digital marketplace. A mad rush of investment in Internet-based businesses led to the dot-com boom through the late 1990s, and then the dot-com bust in 2000. While much can be learned from the speculation and crazy economic theories espoused during that bubble, one important outcome for businesses was that thousands of miles of Internet connections were laid around the world during that time. The world became truly “wired” heading into the new millennium, ushering in the era of globalization, which we will discuss in chapter 11.
As it became more expected for companies to be connected to the Internet, the digital world also became a more dangerous place. Computer viruses and worms, once slowly propagated through the sharing of computer disks, could now grow with tremendous speed via the Internet. Software written for a disconnected world found it very difficult to defend against these sorts of threats. A whole new industry of computer and Internet security arose. We will study information security in chapter 6.
Registered trademark of Amazon Technologies, Inc
As the world recovered from the dot-com bust, the use of technology in business continued to evolve at a frantic pace. Websites became interactive; instead of just visiting a site to find out about a business and purchase its products, customers wanted to be able to customize their experience and interact with the business. This new type of interactive website, where you did not have to know how to create a web page or do any programming in order to put information online, became known as web 2.0. Web 2.0 is exemplified by blogging, social networking, and interactive comments being available on many websites. This new web-2.0 world, in which online interaction became expected, had a big impact on many businesses and even whole industries. Some industries, such as bookstores, found themselves relegated to a niche status. Others, such as video rental chains and travel agencies, simply began going out of business as they were replaced by online technologies. This process of technology replacing a middleman in a transaction is called disintermediation.
As the world became more connected, new questions arose. Should access to the Internet be considered a right? Can I copy a song that I downloaded from the Internet? How can I keep information that I have put on a website private? What information is acceptable to collect from children? Technology moved so fast that policymakers did not have enough time to enact appropriate laws, making for a Wild West–type atmosphere. Ethical issues surrounding information systems will be covered in chapter 12.
The Post-PC World
After thirty years as the primary computing device used in most businesses, sales of the PC are now beginning to decline as sales of tablets and smartphones are taking off. Just as the mainframe before it, the PC will continue to play a key role in business, but will no longer be the primary way that people interact and do business. The limited storage and processing power of these devices is being offset by a move to “cloud” computing, which allows for storage, sharing, and backup of information on a massive scale. This will require new rounds of thinking and innovation on the part of businesses as technology continues to advance.
4. CERN's "The Birth of the Web." http://public.web.cern.ch/public/en/about/web-en.html
The Eras of Business Computing
Terminals connected to mainframe computer.
(TSO) on MVS
IBM PC or compatible. Sometimes connected to mainframe computer via expansion card.
WordPerfect, Lotus 1-2-3
(late 80s to early
IBM PC “clone” on a Novell
Windows for Workgroups
Word, Microsoft Excel
Wide Web (mid-90s to early 2000s)
IBM PC “clone” connected to company intranet.
Office, Internet Explorer
Web 2.0 (mid-2000s to present)
Laptop connected to company
(today and beyond)
Mobile-friendly websites, mobile apps
Can Information Systems Bring Competitive Advantage?
It has always been the assumption that the implementation of information systems will, in and of itself, bring a business competitive advantage. After all, if installing one computer to manage inventory can make a company more efficient, won’t installing several computers to handle even more of the business continue to improve it?
In 2003, Nicholas Carr wrote an article in the Harvard Business Review that questioned this assumption. The article, entitled “IT Doesn’t Matter,” raised the idea that information technology has become just a commodity. Instead of viewing technology as an investment that will make a company stand out, it should be seen as something like electricity: It should be managed to reduce costs, ensure that it is always running, and be as risk-free as possible.
As you might imagine, this article was both hailed and scorned. Can IT bring a competitive advantage? It sure did for Walmart (see sidebar). We will discuss this topic further in chapter 7.
Sidebar: Walmart Uses Information Systems to Become the World’s Leading Retailer
Walmart is the world’s largest retailer, earning $15.2 billion on sales of $443.9 billion in the fiscal year that ended on January 31, 2012. Walmart currently serves over 200 million customers every week, worldwide.5 Walmart’s rise to prominence is due in no small part to their use of information systems.
One of the keys to this success was the implementation of Retail Link, a supply-chain management system. This system, unique when initially implemented in the mid-1980s, allowed Walmart’s suppliers to directly access the inventory levels and sales information of their products at any of Walmart’s more than ten thousand stores. Using Retail Link, suppliers can analyze how well their products are selling at one or more Walmart stores, with a range of reporting options. Further, Walmart requires the suppliers to use Retail Link to manage their own inventory levels. If a supplier feels that their products are selling out too quickly, they can use Retail Link to petition Walmart to raise the levels of inventory for their products. This has essentially allowed Walmart to “hire” thousands of product managers, all of whom have a vested interest in the products they are managing. This revolutionary approach to managing inventory has allowed Walmart to continue to drive prices down and respond to market forces quickly.
Registered trademark of Wal-Mart Stores, Inc
Today, Walmart continues to innovate with information technology. Using its tremendous market presence, any technology that Walmart requires its suppliers to implement immediately becomes a business standard.
In this chapter, you have been introduced to the concept of information systems. We have reviewed several definitions, with a focus on the components of information systems: technology, people, and process. We have reviewed how the business use of information systems has evolved over the years, from the use of large mainframe computers for number crunching, through the introduction of the PC and networks, all the way to the era of mobile computing. During each of these phases, new innovations in software and technology allowed businesses to integrate technology more deeply.
We are now to a point where every company is using information systems and asking the question: Does it bring a competitive advantage? In the end, that is really what this book is about. Every businessperson should understand what an information system is and how it can be used to bring a competitive advantage. And that is the task we have before us.
1. What are the five components that make up an information system?
2. What are three examples of information system hardware?
3. Microsoft Windows is an example of which component of information systems?
4. What is application software?
5. What roles do people play in information systems?
6. What is the definition of a process?
7. What was invented first, the personal computer or the Internet (ARPANET)?
8. In what year were restrictions on commercial use of the Internet first lifted? When were eBay and Amazon founded?
9. What does it mean to say we are in a “post-PC world”?
10. What is Carr’s main argument about information technology?
5. Walmart 2012 Annual Report.
1. Suppose that you had to explain to a member of your family or one of your closest friends the concept of an information system. How would you define it? Write a one-paragraph description in your own words that you feel would best describe an information system to your friends or
2. Of the five primary components of an information system (hardware, software, data, people, process), which do you think is the most important to the success of a business organization? Write a one-paragraph answer to this question that includes an example from your personal experience to support your answer.
3. We all interact with various information systems every day: at the grocery store, at work, at school, even in our cars (at least some of us). Make a list of the different information systems you interact with every day. See if you can identify the technologies, people, and processes involved
in making these systems work.
4. Do you agree that we are in a post-PC stage in the evolution of information systems? Some people argue that we will always need the personal computer, but that it will not be the primary device used for manipulating information. Others think that a whole new era of mobile and biological computing is coming. Do some original research and make your prediction about what business computing will look like in the next generation.
5. The Walmart case study introduced you to how that company used information systems to become the world’s leading retailer. Walmart has continued to innovate and is still looked to as a leader in the use of technology. Do some original research and write a one-page report detailing a new technology that Walmart has recently implemented or is pioneering.
Upon successful completion of this chapter, you will be able to:
• describe information systems hardware;
• identify the primary components of a computer and the functions they perform; and
• explain the effect of the commoditization of the personal computer.
As we learned in the first chapter, an information system is made up of five components: hardware, software, data, people, and process. The physical parts of computing devices – those that you can actually touch – are referred to as hardware. In this chapter, we will take a look at this component of information systems, learn a little bit about how it works, and discuss some of the current trends surrounding it.
As stated above, computer hardware encompasses digital devices that you can physically touch. This includes devices such as the following:
• desktop computers
• laptop computers
• mobile phones
• tablet computers
• storage devices, such as flash drives
• input devices, such as keyboards, mice, and scanners
• output devices such as printers and speakers.
Besides these more traditional computer hardware devices, many items that were once not considered digital devices are now becoming computerized themselves. Digital technologies are now being integrated into many everyday objects, so the days of a device being labeled categorically as computer hardware may be ending. Examples of these types of digital devices include automobiles, refrigerators, and even soft- drink dispensers. In this chapter, we will also explore digital devices, beginning with defining what we mean by the term itself.
A digital device processes electronic signals that represent either a one (“on”) or a zero (“off”). The on state is represented by the presence of an electronic signal; the off state is represented by the absence of an electronic signal. Each one or zero is referred to as a bit (a contraction of binary digit); a group of eight bits is a byte. The first personal computers could process 8 bits of data at once; modern PCs can now process 64 bits of data at a time, which is where the term 64-bit processor comes from.
Sidebar: Understanding Binary
As you know, the system of numbering we are most familiar with is base-ten numbering. In base-ten numbering, each column in the number represents a power of ten, with the far-right column representing 10^0 (ones), the next column from the right representing 10^1 (tens), then 10^2 (hundreds), then 10^3 (thousands), etc. For example, the number 1010 in decimal represents: (1 x 1000) + (0 x 100) + (1 x 10) + (0 x 1).
Computers use the base-two numbering system, also known as binary. In this system, each column in the number represents a power of two, with the far-right column representing 2^0 (ones), the next column from the right representing 2^1 (tens), then 2^2 (fours), then 2^3 (eights), etc. For example, the number 1010 in binary represents (1 x 8 ) + (0 x 4) + (1 x 2) + (0 x 1). In base ten, this evaluates to 10.
As the capacities of digital devices grew, new terms were developed to identify the capacities of processors, memory, and disk storage space. Prefixes were applied to the word byte to represent different orders of magnitude. Since these are digital specifications, the prefixes were originally meant to represent multiples of 1024 (which is 210), but have more recently been rounded to mean multiples of 1000.
A Listing of Binary Prefixes
kilobyte=one thousand bytes
megabyte=one million bytes
gigabyte=one billion bytes
terabyte=one trillion bytes
Tour of a PC
All personal computers consist of the same basic components: a CPU, memory, circuit board, storage, and input/output devices. It also turns out that almost every digital device uses the same set of components, so examining the personal computer will give us insight into the structure of a variety of digital devices. So let’s take a “tour” of a personal computer and see what makes them function.
Processing Data: The CPU
As stated above, most computing devices have a similar architecture. The core of this architecture is the central processing unit, or CPU. The CPU can be thought of as the “brains” of the device. The CPU carries out the commands sent to it by the software and returns results to be acted upon.
The earliest CPUs were large circuit boards with limited functionality. Today, a CPU is generally on one chip and can perform a large variety of functions. There are two primary manufacturers of CPUs for personal computers: Intel and Advanced Micro Devices (AMD).
The speed (“clock time”) of a CPU is measured in hertz. A hertz is defined as one cycle per second. Using the binary prefixes mentioned above, we can see that a kilohertz (abbreviated kHz) is one thousand cycles per second, a megahertz (mHz) is one million cycles per second, and a gigahertz (gHz) is one billion cycles per second. The CPU’s processing power is increasing at an amazing rate (see the sidebar about Moore’s Law). Besides a faster clock time, many CPU chips now contain multiple processors per chip. These chips, known as dual-core (two processors) or quad-core (four processors), increase the processing power of a computer by providing the capability of multiple CPUs.
Sidebar: Moore’s Law
We all know that computers get faster every year. Many times, we are not sure if we want to buy today’s model of smartphone, tablet, or PC because next week it won’t be the most advanced any more. Gordon Moore, one of the founders of Intel, recognized this phenomenon in 1965, noting that microprocessor transistor counts had been doubling every year.1 His insight eventually evolved into Moore’s Law, which states that the number of transistors on a chip will double every two years. This has been generalized into the concept that computing power will double every two years for the same price point. Another way of looking at this is to think that the price for the same computing power will be cut in half every two years. Though many have predicted its demise, Moore’s Law has held true for over forty years (see figure below).
1. Moore, Gordon E. (1965). "Cramming more components onto integrated circuits" (PDF). Electronics Magazine. p. 4. Retrieved
A graphical representation of Moore’s Law (CC-BY-SA: Wgsimon)
There will be a point, someday, where we reach the limits of Moore’s Law, where we cannot continue to shrink circuits any further. But engineers will continue to seek ways to increase performance.
Motherboard (click image to enlarge)
The motherboard is the main circuit board on the computer. The CPU, memory, and storage components, among other things, all connect into the motherboard. Motherboards come in different shapes and sizes, depending upon how compact or expandable the computer is designed to be. Most modern motherboards have many integrated components, such as video and sound processing, which used to require separate components.
The motherboard provides much of the bus of the computer (the term bus refers to the electrical connection between different computer components). The bus is an important determiner of the computer’s speed: the combination of how fast the bus can transfer data and the number of data bits that can be moved at one time determine the speed.
When a computer starts up, it begins to load information from the hard disk into its working memory. This working memory, called random-access memory (RAM), can transfer data much faster than the hard disk. Any program that you are running on the computer is loaded into RAM for processing. In order for a computer to work effectively, some minimal amount of RAM must be installed. In most cases, adding more RAM will allow the computer to run faster. Another characteristic of RAM is that it is “volatile.” This means that it can store data as long as it is receiving power; when the computer is turned off, any data stored in RAM is lost.
RAM is generally installed in a personal computer through the use of a dual-inline memory module (DIMM). The type of DIMM accepted into a computer is dependent upon the motherboard. As described by Moore’s Law, the amount of memory and speeds of DIMMs have increased dramatically over the years.
Memory DIMM (click image to enlarge)
Hard disk enclosure (click image to enlarge)
While the RAM is used as working memory, the computer also needs a place to store data for the longer term. Most of today’s personal computers use a hard disk for long-term data storage. A hard disk is where data is stored when the computer is turned off and where it is retrieved from when the computer is turned on. Why is it called a hard disk? A hard disk consists of a stack of disks inside a hard metal case. A floppy disk (discussed below) was a removable disk that, in some cases at least, was flexible, or “floppy.”
A relatively new component becoming more common in some personal computers is the solid-state drive (SSD). The SSD performs the same function as a hard disk: long-term storage. Instead of spinning disks, the SSD uses flash memory, which is much faster.
Solid-state drives are currently quite a bit more expensive than hard disks. However, the