Computer Software

Software, also called a program, consists of a series of related instructions, organized for a common purpose, that tells the computer what tasks to perform and how to perform them.

 You interact with a program through its user interface. The user interface controls how you enter data and instructions and how information is displayed on the screen. Software today often has a graphical user interface (GUI), you interact with the software using text, graphics, and visual images such as icons. 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.

System 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.

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 computer and other software. Many of today's computers use Microsoft's Windows, or Mac OS, Apple's operating system.

 When a user starts a computer, portions of the operating system are copied into memory from the computer's hard disk. These parts of the operating system remain 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. For example, you can use a utility program to transfer digital photos to an optical disc. Most operating systems include several utility programs for managing disk drives, printers, and other devices and media. You also can buy utility programs that allow you to perform additional computer management functions.

Application Software

 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 or access programs. Other popular application software includes word processing software, spreadsheet software, database software, and presentation 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, document management, computer-aided design, desktop publishing, paint/image editing, photo editing,audio and video editing, multimedia authoring, Web page authoring, personal finance, legal, tax preparation, home design/landscaping, travel and mapping, education, reference, and entertainment (e.g., games or simulations, etc.).

 Software is available at stores that sell computer products and also online at many Web sites.

Installing and Running Programs

 When purchasing software from a retailer, you typically receive a box that includes an optical disc(s) that contains the program. If you acquire software from a Web site on the Internet, you may be able to download the program; that is, the program transfers from the Web site to the hard disk in your computer.

 The instructions in software are placed on storage media, either locally or online. To use software that is stored locally, such as on a hard disk or optical disc, you usually need to install the software. Web applications that are stored online, by contrast, usually do not need to be installed.

 Installing is the process of setting up software to work with the computer, printer, and other hardware. When you buy a computer, it usually has some software preinstalled on its hard disk. This enables you to use the computer the first time you turn it on. To begin installing additional software from an optical disc, insert the program disc in an optical disc drive and follow the instructions to begin installation. To install downloaded software, the Web site typically provides instructions for how to install the program on your hard disk.

 Once installed, you can run the program. When you instruct the computer to run an installed program, the computer loads it, which means the program is copied from storage to memory. Once in memory, the computer can carry out, or execute, the instructions in the program so that you can use the program.

Software Development

 A programmer, sometimes called a computer programmer or developer, is someone who develops software or writes the instructions that direct computer to process data into information. When writing instructions, a programmer must be sure the program works properly so that the computer generates the desired results. Complex programs can require thousands to millions of instructions.

 Programmers use a programming language or program development tool to create computer programs. Popular programming languages include C++, Java, JavaScript, Visual C#, and Visual Basic.

Networks and the Internet

A network is a collection of computers and devices connected together, often wirelessly, 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. In many networks, one or more computers act as a server. The server controls access to the resources on a network. The other computers on the network, each called a client or workstation, request resources from the server. The major differences between the server and client computers are that the server ordinarily has more power, more storage space, and expanded communications capabilities.

 Many homes and most businesses and schools network their computers and devices. Most allow users to connect their computer wirelessly to the network. Home networks usually are small, existing within a single structure. Business and school networks can be small, such as in a room or building, or widespread, connecting computers and devices across a city, country, or the globe. The world's largest computer network is the Internet.

The Internet

 The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals.

 More than one billion people around the world use the Internet daily for a variety of reasons, some of which are listed below:

• Communicate with and meet other people
• Conduct research and access a wealth of information and news
• Shop for goods and services
• Bank and invest
• Participate in online training
• Engage in entertaining activities, such as planning vacations, playing online game, listening to music, watching or editing videos, and reading books and magazines
• Download music and videos
• Share information, photos, and videos
• Access and interact with Web applications

 People connect to the Internet to share information with others around the world. E-mail allows you to send and receive messages to and from 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. You also can use the Internet to make a telephone call.

 Businesses, called access providers, offer users and organizations access to the Internet free or for a fee. By subscribing to an access provider, you can use your computer and a communications device, such as 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. Think of the Web as a global library of information available to anyone connected to the Internet. The Web contains billions of documents called Web pages. A Web page can contain text, graphics, animation, audio, and video. 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. Some Web sites allow users to access music and videos that can be downloaded, you can listen to the music through speakers, headphones, or earbuds, or view the videos on a display device.

 Many people use the Web as a means to share personal information, photos, and videos with the world. For example, you can create a Web page and then make it available, or publish it, on the Internet for others to see.

 You also can join millions of people worldwide in an online community, called a social networking Web site or an online social network, that encourages members to share their interests, ideas, stories, photos, musics,and videos with other registered users. Some social networking Web sites are college oriented, some business oriented, and others are more focused. A photo sharing community,  for example, is a specific type of social networking Web site that allows users to create an online photo album and store and share their digital photos. Similarly, a video sharing community is a type of social networking Web site that allows users to store and share their personal videos.

 Hundreds of thousands of people today also use blogs to publish their thoughts on the Web. A blog is an informal Web site consisting of time-stamped articles in a diary or journal format, usually listed in reverse chronological order. As others read the articles in a blog, they reply with their own thoughts. A blog that contains video clips is called a video blog. A microblog, such as Twitter, allows users to publish short messages, usually between 100 and 200 characters, for others to read.

 Podcast are a popular way people verbally share information on the Web. A podcast is recorded audio stored on a Web site that can be downloaded to a computer or a portable media player such as an iPod. A video podcast is a podcast that contains video and usually audio. At a convenient time and location, the user listens to or watches the downloaded podcast.

 A Web application is a Web site that allows users to access and interact with software from any computer or device that is connected to the Internet. Examples of software available as Web applications include those that allow you to send and receive e-mail messages, prepare your taxes, organize digital photos, create documents, and play games.

 Web sites such as social networking Web sites, blogs, and Web applications are categorized as Web 2.0 site. The term Web 2.0 refers to Web sites that provide a means for users to share personal information (such as social networking Web sites), allow users to modify the Web site contents (such as some blogs), and/or have software built into the site for users to access ( such as Web applications).

Advantages and Disadvantages of Using Computers

Society has reaped many benefits from using computers. A user is anyone who communicates with a computer or utilizes the information it generates. Both business and home users can make well-informed decisions because they have instant access to information from anywhere in the world. Students, another type of user, have more tools to assist hem in the learning process.

Advantages of Using Computers

 Benefits from using computers are possible because computers have the advantages of speed, reliability, consistency, storage, and communications.

• Speed: When data, instructions, and information flow along electronic circuits in a computer, they travel at incredibly fast speeds. Many computers process billions or trillions of operations in a single second. Processing involves computing (e.g., adding, subtracting), sorting (e.g., alphabetizing), organizing, displaying images, recording audio, playing music, and showing a movie or video.
• Reliability: The electronic components in modern computers are dependable and reliable because they rarely break or fail.
• Consistency: Given the same input and process, a computer will produce the same results – consistently. A computing phrase – know as garbage in, garbage out – points out that the accuracy of a computer's output depends on the accuracy of the input. For example, if you do not use the flash on a digital camera when indoors, the resulting pictures that are displayed on the computer screen may be unusable because they are too dark.
• Storage: A computer can transfer data quickly from storage to memory, process it, and then store it again for future use. Many 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 with this capability can share any of the four information processing cycle operations – input, process, output, and storage – with another computer or a user.

Disadvantage of Using Computers

 Some disadvantages of computers relate to health risks, the violation of privacy, public safety, the impact on the labor force, and the impact on the environment.

• Health Risks: Prolonged or improper computer use can lead to injuries or disorder of the hands, wrists, elbows, eyes, neck, and back. Computer users can protect themselves from these health risks through proper workplace design, good posture while at the computer,and appropriately spaced work breaks. Two behavioral health risks are computer addiction and technology overload. Computer addiction occurs when someone becomes obsessed with using a computer. Individuals suffering from technology overload feel distressed when deprived of computers and mobile devices. Once recognized, both computer addiction and technology overload are treatable disorders.
• Violation of Privacy: Nearly every life event is stored in a computer somewhere... in medical records, credit reports, tax records, etc. In many instances, where personal and confidential records were not protected properly, individuals have found their privacy violated and identities stolen.
• Public Safety: Adults, teens, and children around the world are using computers to share publicly their photos, videos, journals, musics, and other personal information. Some of these unsuspecting, innocent computer users have fallen victim to crimes committed by dangerous strangers. Protect yourself and your dependents from these criminals by being cautions in e-mail messages and on Web sites. For example, do not share information that would allow others to identify and locate you and do not disclose identification numbers, passwords, or other personal security details
• Impact on Labor Force: Although computers have improved productivity in many ways 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.
• Impact on Environment: Computer manufacturing processes and computer waste are depleting natural resources and polluting the environment. When computers are discarded in landfills, they can release toxic materials and potentially dangerous levels of lead, mercury, and flame retardants.

Green computing involves reducing the electricity consumed and environmental waste generated when using a computer. Strategies that support green computing include recycling, regulating manufacturing processes, extending the life of computers, and immediately donating or properly disposing of replaced computers. When you purchase a new computer, some retailers offer to dispose of your old computer properly.

The Components of a Computer

A computer contains many electric, electronic, and mechanical components know as hadware. These components include input devices, output devices, a system unit, storage devices, and communications devices.

Input Devices

 An input device is any hardware component that allows you to enter data and instructions into a computer. Five widely used input devices are the keyboard, mouse, microphone, scanner, and Web cam.

  A computer keyboard contains keys you press to enter data into the computer. For security purposes, some keyboards include a fingerprint reader, which allows you to work with the computer only if your fingerprint is recognized.

 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 you to speak into the computer. A scanner converts printed material (such as text and pictures) into a form the computer can use.

 A Web cam is a digital video camera that allows you to create movies or take pictures and store them on the computer instead of on tape or film.

Output 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.

 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).

System Unit

 The system unit is a case that contains the electronic components of the computer that are used to process data. 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 a CPU (central processing unit), is the electronic component that interprets and carries out the basic instructions. Although some forms of memory are permanent, most memory keeps data and instructions temporarily, which means its contents are erased when the computer is shut off.

Storage Devices

 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 USB flash drives, hard disks, optical discs, and memory cards. A storage device records (writes) and/or retrieves (reads) items to and from storage media. Drives and readers/writers, which are types of storage devices, accept a specific kind of storage media. For example, a DVD drive (storage device) accepts a DVD (storage media). Storage devices often function as a source of input because they transfer items from storage to memory.

 A USB flash drive is a portable storage device that is small and lightweight enough to be transported on a keychain or in a pocket. The average USB flash drive can hold about 4 billion characters. You plug a USB flash drive in a special, easily accessible opening on the computer.

 A hard disk provides much greater storage capacity than a USB flash drive. The average hard disk can hold more than 320 billion characters. Hard disks are enclosed in an airtight, sealed case. Although some are portable, most are housed inside the system unit. Portable hard disks are either external or removable. An external hard disk is a separate, freestanding unit, whereas you insert and remove a removable hard disk from the computer or a device connected to the computer.

 An optical disc is a flat, round, portable metal disc with a plastic coating. CDs, DVDs, and Blu-ray Discs are three types of optical discs. A CD can hold 650 million to 1 billion characters. Some DVDs can store two full-length movies or 17 billion characters. Blu-ray Discs can store about 46 hours of standard video, or 100 billion characters.

 Some mobile devices, such as digital cameras, use memory cards as the storage media. You can use a card reader/writer to transfer the stored items, such as digital photos, from the memory card to a computer or printer.  

Communications Devices

 A communication 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 or mobile devices. A widely used communications device is a modem.

 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.

What is a computer?

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.

Data and Information

 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.

Many daily activities either involve the use of or depend on information from a computer.

Information Processing Cycle

 Computers process data (input) into information (output). Computers carry out process using instructions, which are the steps that tell the computer how to perform a particular task. A collection of related instructions organized for a common purpose is referred to as software. A computer often holds data, information, and instructions in storage for future use. Some people refer to the series of input, process, output, and storage activities as the information processing cycle.

 Most computers today communicate with other computers. As a result, communications also has become an essential element of the information processing cycle.