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Chapter 1: Introduction to Computers
OBJECTIVES:
After completing this chapter, you will be able to:
1. Recognize the importance of computer literacy
2. Identify the components of a computer
3. Discuss the uses of the Internet and World Wide Web
4. Identify the categories of software
5. Describe the categories of computers
6. Identify the types of computer users
7. Discuss various computer applications in society
CONTENTS:
A WORLD OF COMPUTERS
WHAT IS A COMPUTER?
Data and Information
Advantages and Disadvantages of Using Computers
Information Processing Cycle
THE COMPONENTS OF A COMPUTER
Input Devices
Output Devices
System Unit
Storage Devices
Communications Devices
NETWORKS AND THE INTERNET
The Internet
COMPUTER SOFTWARE
System Software
Application Software
Installing and Running Programs
Software Development
CATEGORIES OF COMPUTERS PERSONAL COMPUTERS
Desktop Computers
MOBILE COMPUTERS AND MOBILE DEVICES
Notebook Computers
Mobile Devices
MIDRANGE SERVERS
MAINFRAMES
SUPERCOMPUTERS
EMBEDDED
COMPUTERS
EXAMPLES OF COMPUTER USAGE
Home User
Small Office/Home Office User
Mobile User
Power User
Large Business User
COMPUTER APPLICLTIONS IN SOCIETY
Education
Finance
Government
Health Care
Science
Publishing
Travel
Industry
CHAPTER SUMMARY
COMPANIES ON THE CUTTING EDGE
Dell
Apple Company
TECHNOLOGY TRAILBLAZERS
Bill Gates
Carly Fiorina
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Computers are everywhere: at work, at school, and at home (Figure 1-1). They are a primary means of communication for billions of people. Employees correspond with clients, students with teachers, and family with friends and other family members.
Through computers, society has instant access to information from around the globe. Local and national news, weather reports, sports scores, airline schedules, telephone directories, maps and directions, job listings, credit reports, and countless forms of educational material always are accessible. From the computer, you can meet new friends, share photographs and videos, shop, fill prescriptions, file taxes, or take a course.
In the workplace, employees use computers to create correspondence such as e-mail messages, memos, and letters; calculate payroll; track inventory; and generate invoices. Some applications such as automotive design and weather forecasting use computers to perform complex mathematical calculations. At school, teachers use computers to assist with classroom instruction. Students use computers to complete assignments and research.
People also spend hours of leisure time on the computer. They play games, listen to music, watch videos and movies, read books and magazines, research genealogy, compose music and videos, retouch photographs, and plan vacations.
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Many people believe that computer literacy is vital to success. Computer literacy involves having a knowledge and understanding of computers and their uses.
This hook presents the knowledge you need to he computer literate. As you read this first chapter, keep in mind it is an overview. Many of the terms and Concepts introduced in this chapter will he discussed in more depth later in the book.
A computer is an electronic device, operating under the control of instructions stored in its own memory that can accept data, process the data according to specified rules, produce results, and store the results for future use.
Computers process data into information. Data is a collection of unprocessed items,
which can include text, numbers, images, audio, and video Information conveys meaning and is useful to people.
Figure 1-1: People use computers in their daily activities.
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As shown in figure 1-2, for example, computers process several data items to print information in the form of a payroll check.
Society has reaped many benefits from using computers. Both business and home users can make well-informed decisions because they have instant access to information from anywhere in the world. A user is anyone who communicates with a computer or utilizes the information it generates. Students, another type of user, have more tools to assist them in the learning process. Read Looking Ahead 1-1 for a look at the next generation of benefits from using computers.
FIGURE 1-2 A computer processes data into information. In this simplified example, the employee’s name and address, hourly pay rate, and hours worked all represent data. The computer processes the data to produce the payroll check (information).
FAQ 1-1: Is data a singular or plural word?
The word data is plural for datum. With respect to computers, however, it is accepted and common practice to use the word data in both the singular and plural context. For more information, visit scsite.com/dcf2e/chl/taq and then click Data.
An FAQ (frequently asked question) helps you find answers to commonly asked questions. Web sites often post an FAQ section, and each chapter in this book includes FAQ boxes related to topics in the text.
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ADVANTAGES OF USING COMPUTERS
The benefits of computers are possible because computers have the advantages of speed, reliability, consistency, storage, and communications.
• Speed: Computer operations occur through electronic circuits. When data, instructions, and information flow along these circuits, they travel at incredibly fast speeds. Many computers process billions or trillions of operations in a single second.
• Reliability: The electronic components in modern computers are dependable and reliable because they rarely break or fail.
• Consistency: Given the same input and processes, a computer will produce the same results — consistently. Computers generate error-free results, provided the input is correct and the instructions work.
• Storage: Computers store enormous amounts of data and make this data available for processing anytime it is needed.
• Communications: Most computers today can communicate with other computers, often wirelessly. Computers allow users to communicate with one another.
DISADVANTAGES OF USING COMPUTERS
Some disadvantages of computers relate to the violation of privacy, the impact on the labor force, health risks, and the impact on the environment.
• Violation of Privacy: It is crucial that personal and confidential records stored in computers be protected properly. In many instances, where these records were not properly protected, individuals have found their privacy violated and identities stolen.
• Impact on Labor Force: Although computers have improved productivity and created an entire industry with hundreds of thousands of new jobs, the skills of millions of employees have been replaced by computers. Thus, it is crucial that workers keep their education up-to-date. A separate impact on the labor force is that some companies are outsourcing jobs to foreign countries instead of keeping their homeland labor force employed.
• Health Risks: Prolonged or improper computer use can lead to health injuries or disorders. Computer users can protect themselves from health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks.
• Impact on Environment:
Computer manufacturing processes and computer waste are depleting natural resources and polluting the environment. Strategies that can help protect the environment include recycling, regulating manufacturing processes, extending the life of computers, and immediately donating replaced computers.
Bionic People Benefit from Computer Implants
Computers eventually will become an integral part of the human body. They already are used to help some hearing-impaired people hear by stimulating the nerves within the ear and to help the vision-impaired to see by converting light into electrical impulses.
The next step will involve implanting miniature computers or computer components in the body to help it perform basic functions. A miniature computer, for example, could help release hormones. A brain computer interface may monitor and treat diseases, such as epilepsy and depression, that affect brain activity. A body-scanning machine will evaluate patients’ pain when they cannot communicate.
In addition, robotic legs strapped to the body can assist people such as firefighters and soldiers who must bear heavy loads for extended periods of time. For more information, visit scsite.com/dcf2e/chl/looking and then click Computer Implants.
Computers process data (input) into information (output). A computer often holds data, information, and instructions in storage for future use. Instructions are the steps that tell the computer how to perform a particular task. Some people refer to the series of input, process, output, and storage activities as the information processing cycle. Recently, communications also has become an essential element of the information processing cycle.
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A computer contains many electric, electronic, and mechanical components known as hardware. These components include input devices, output devices, a system unit, storage devices, and communications devices. Figure 1-3 shows some common computer hardware components.
An input device is any hardware component that allows you to enter data and instructions into a computer. Six widely used input devices are the keyboard, mouse, microphone, scanner, digital camera, and PC video camera (Figure 1-3).
A computer keyboard contains keys you press to enter data into the computer. A mouse is a small handheld device. With the mouse, you control movement of a small symbol on the screen, called the pointer, and you make selections from the screen.
A microphone allows a user to speak into the computer to enter data and instructions. A scanner converts printed material (such as text and pictures) into a form the computer can use.
With a digital camera, you take pictures and then transfer the photographed images to the computer or printer instead of storing the images on traditional film. A PC video camera is a digital video camera that allows users to create a movie or take still photographs electronically.
FIGURE 1-3 Common computer hardware components include the keyboard, mouse, microphone, scanner, digital camera, PC video camera, printer, monitor, speakers, system unit, disk drives, USB flash drive, card reader/writer, and modem.
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Input Devices For more information, visit scsite.comldcf2e/ chi/weblink and then click Input Devices.
An output device is any hardware component that conveys information to one or more people. Three commonly used output devices are a printer, a monitor, and speakers (Figure 1-3).
A printer produces text and graphics on a physical medium such as paper. A monitor displays text, graphics, and videos on a screen. Speakers allow you to hear music, voice, and other audio (sounds).
The system unit is a case that contains electronic components of the computer that are used to process data (Figure 1-3). The circuitry of the system unit usually is part of or is connected to a circuit board called the motherboard.
Two main components on the motherboard are the processor and memory. The processor, also called the central processing unit (CPU), is the electronic component that interprets and carries out the basic instructions that operate the computer. Memory consists of electronic components that store instructions waiting to be executed and data needed by those instructions. Most memory keeps data and instructions temporarily, which means its contents are erased when the computer is shut off.
Storage holds data, instructions, and information for future use. For example, computers can store hundreds or millions of customer names and addresses. Storage holds these items permanently.
A computer keeps data, instructions, and information on storage media. Examples of storage media are floppy disks, USB flash drives, hard disks, CDs, DVDs, and memory cards. A storage device records (writes) and/or retrieves (reads) items to and from storage media. Storage devices often function as a source of input because they transfer items from storage to memory.
A floppy disk consists of a thin, circular, flexible disk enclosed in a square-shaped plastic shell. A typical floppy disk stores up to about 1.4 million characters. You insert a floppy disk in and remove it from a floppy disk drive.
A USB flash drive is a portable storage device that has much more storage capacity than a floppy disk but is small and lightweight enough to be transported on a keychain or in a pocket (Figure 1-3).
A hard disk provides much greater storage capacity than a floppy disk or USB flash drive. The average hard disk can hold more than 80 billion characters. Hard disks are enclosed in an airtight, sealed case. Although some are removable, most are housed inside the system unit (Figure 1-4).
A compact disc is a flat, round, portable metal disc with plastic coating. One type of compact disc is a CD-ROM, which you can access using most CD and DVD drives (Figure 1-5). Another type of compact disc is a DVD-ROM, which has enough storage capacity to store two full-length movies. To access a DVD-ROM, you need a DVD drive.
Some portable devices, such as digital cameras, use memory cards as the storage media. You can use a card reader/writer (Figure 1-3) to transfer stored items, such as electronic photographs, from the memory card to a computer or printer.
FIGURE 1.4 Most hard disks are housed inside the system unit.
FIGURE 1-5 To use a CD or DVD, you need a CD or DVD drive.
For more information, visit scsite.com/dcf2e/ chi/weblink and then click Output Devices.
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A communications device is a hardware component that enables a computer to send (transmit) and receive data, instructions, and information to and from one or more computers. A widely used communications device is a modem (Figure 1-3 on page 6).
Communications occur over cables, telephone lines, cellular radio networks, satellites, and other transmission media. Some transmission media, such as satellites and cellular radio networks, are wireless, which means they have no physical lines or wires.
Test your knowledge of pages 2 through 8 in Quiz Yourself 1-1.
Instructions: Find the true statement below. Then, rewrite the remaining false statements so they are true.
1 A computer is a motorized device that processes output into input
2 A storage device records (reads) and/or retrieves (writes) items to and from storage media
3 An output device is any hardware component that allows you to enter data and instructions into a computer
4 Computer literacy involves having a knowledge and understanding of computers and their uses
5. Three commonly used input devices are a printer, a monitor, and speakers.
Quiz Yourself Online: To further check your knowledge of computer literacy and computer components, visit scsite.com/dcf2e/chl/quiz and then click Objectives 1 — 2.
A network is a collection of computers and devices connected together via communications devices and transmission media. When a computer connects to a network, it is online. Networks allow computers to share resources, such as hardware, software, data, and information. Sharing resources saves time and money.
The Internet is a worldwide collection of networks that connects millions of businesses,
government agencies, educational institutions, and individuals (Figure 1-6).
FIGURE 1-6 The Internet is the largest computer network, connecting millions of computers around the world.
For more information, visit scsite.com/dcf2e/ chl/weblink and then click Communications Devices.
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More than one billion people around the world use the Internet daily for a variety of reasons, including the following purposes:
• Communicate with and meet other people
• Access a wealth of information, news, and research findings
• Shop for goods and services
• Bank and invest
• Take a class
• Access sources of entertainment and leisure, such as online games, music, videos, books, and magazines
Figure 1-7 shows examples in each of these areas.
The Internet For more information, visit scsite.com/dcf2e/ chi/weblink and then click Internet.
FIGURE 1-7 Users access the Internet for a variety of reasons: to communicate with others, to access a wealth of information, to shop for goods and services, to bank and invest, to take a class, and for entertainment.
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People connect to the Internet to exchange information with others around the world. E-mail allows you to send messages to other users. With instant messaging, you can have a live conversation with another connected user. In a chat room, you can communicate with multiple users at the same time — much like a group discussion.
Businesses, called access providers, offer access to the Internet free or for a fee. By subscribing to an access provider, you can use your computer and a modem to connect to the many services of the Internet.
The Web, short for World Wide Web, is one of the more popular services on the Internet. The Web contains billions of documents called Web pages. A Web page can contain text, graphics, audio, and video. The six screens shown in Figure 1-7 on the previous page are examples of Web pages.
Web pages often have built-in connections, or links, to other documents, graphics, other Web pages, or Web sites. A Web site is a collection of related Web pages. Anyone can create a Web page and then make it available, or publish it, on the Internet for others to see.
Software, also called a program, is a series of instructions that tells the computer what to do and how to do it.
You interact with a program through its user interface. Software today often has a graphical user interface. With a graphical user interface (GUI pronounced gooey), you interact with the software using text, graphics, and visual images such as icons (Figure 1-8). An icon is a miniature image that represents a program, an instruction, or some other object. You can use the mouse to select icons that perform operations such as starting a program.
The two categories of software are system software and application software. The following sections describe these categories of software.
System software consists of the programs that control or maintain the operations of the computer and its devices. System software serves as the interface between the user, the application software, and the computer’s hardware. Two types of system software are the operating system and utility programs.
FAQ 1-2- What do consumers buy on the Internet?
A recent survey found that online consumers spend the most on clothing, as shown in the chart below. For more information, visit scsite.com/ dcf2e/chl/faq and then click Internet Purchases.
For more information, visit scsite.com/ dcf2e/chl/weblink and then click Computer Programs.
FIGURE 1-8 The graphical user interface of Windows XP.
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OPERATING SYSTEM
An operating system is a set of programs that coordinates all the activities among computer hardware devices. It provides a means for users to communicate with the com puter and other software. Many of today’s computers use Microsoft’s operating system, called Windows XP (Figure 1-8).
When a user starts a computer, portions of the operating system load into memory from the computer’s hard disk. It remains in memory while the computer is on.
UTILITY PROGRAM
A utility program allows a user to perform maintenance-type tasks usually related to managing a computer, its devices, or its programs. Most operating systems include several utility programs for managing disk drives, printers, and other devices. You also can buy utility programs that allow you to perform additional computer management functions.
Application software consists of programs designed to make users more productive and/or assist them with personal tasks. A widely used type of application software related to communications is a Web browser, which allows users with an Internet connection to access and view Web pages. Other popular application software includes word processing software, spreadsheet software, database software, and presentation graphics software.
Many other types of application software exist that enable users to perform a variety of tasks. These include personal information management, note taking, project management, accounting, computer-aided design, desktop publishing, paint/image editing, audio and video editing, multimedia authoring, Web page authoring, personal finance, legal, tax preparation, home design/ landscaping, education, reference, and entertainment (e.g., games or simulations). As shown in Figure 1-9, you often purchase application software from a store that sells computer products. Rea...
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