chapter 01

Software

A program consists of the step-by-step instructions that tell the computer how to do its work. Software is another name for a program or programs. The purpose of software is to convert data (unprocessed facts) into information (processed facts). For example, a payroll program would instruct the computer to take the number of hours you worked in a week (data) and multiply it by your pay rate (data) to determine how much you are paid for the week (information).

Communication

At one time, it was uncommon for a personal computer system to communicate with other computer systems. Now, using communication devices, a personal computer routinely communicates with other computer systems located as near as the next office or as far away as halfway around the world, using the Internet. A modem is a widely used communication device that modifies audio, video, and other types of data into a form that can be transmitted across the Internet.

Four common types of files

Document files,Worksheet files,Database files,Presentation files

Hardware

The equipment that processes the data to create information is called hardware. It includes smartphones, tablets, keyboards, mice, displays, system units, and other devices. Hardware is controlled by software.

Data

The raw, unprocessed facts, including text, numbers, images, and sounds, are called data. Processed data yields information. Using the previous example of a payroll program, the data (number of hours worked and pay rate) is processed (multiplied) to yield information (weekly pay).

System unit

The system unit is a container that houses most of the electronic components that make up a computer system. Two important components of the system unit are microprocessors and memory. (See Figure 1-14.) The microprocessor controls and manipulates data to produce information. Memory is a holding area for data, instructions, and information. One type, random-access memory (RAM), holds the program and data that is currently being processed. This type of memory is sometimes referred to as temporary storage because its contents will typically be lost if the electric power to the computer is disrupted.

General-purpose applications

They are the kinds of programs you have to know to be considered an efficient and effective end user

Secondary storage

Unlike memory, secondary storage holds data and programs even after electric power to the computer system has been turned off. The most important kinds of secondary media are hard disks, solid-state storage, and optical discs.

Midrange computers

also referred to as servers, are computers with processing capabilities less powerful than a mainframe computer yet more powerful than a personal computer. Originally used by medium-size companies or departments of large companies to support their processing needs, today midrange computers are most widely used to support or serve end users for such specific needs as retrieving data from a database or supplying access to application software.

Mobile apps, also known as mobile applications or simply apps

are small programs primarily designed for mobile devices such as smartphones and for tablet computers

Personal computers, also known as PCs

are the least powerful, yet the most widely used and fastest-growing type of computer. There are five types of personal computers: desktops, laptops, tablets, smartphones, and wearables. Desktop computers are small enough to fit on top of or alongside a desk yet are too big to carry around. (See Figure 1-9.) Laptop computers, also known as notebook computers, are portable and lightweight and fit into most briefcases. (See Figure 1-10.) Tablets, also known as tablet computers, are smaller, lighter, and generally less powerful than laptops.

Worksheet files

created by electronic spreadsheets to analyze things like budgets and to predict sales.

Presentation files

created by presentation graphics programs to save presentation materials. For example, a file might contain audience handouts, speaker notes, and electronic slides.

Document files

created by word processors to save documents such as memos, term papers, and letters

Application software

described as end user software. Three types of application software are general-purpose, specialized, and apps.

standalone operating system

for desktop computers

Wireless communication

has changed the way we communicate with one another. The rapid development and widespread use of wireless communication devices like tablets, smartphones, and wearable devices has led many experts to predict that wireless applications are just the beginning of the wireless revolution, a revolution that will dramatically affect the way we communicate and use computer technology.

Procedures

he rules or guidelines for people to follow when using software, hardware, and data are procedures. These procedures are typically documented in manuals written by computer specialists. Software and hardware manufacturers provide manuals with their products. These manuals are provided in either printed or electronic form.

Specialized applications

include thousands of other programs that are more narrowly focused on specific disciplines and occupations. Two of the best known are graphics and web authoring programs.

NOS

network operating system

Mainframe computers

occupy specially wired, air-conditioned rooms. Although not nearly as powerful as supercomputers, mainframe computers are capable of great processing speeds and data storage. For example, insurance companies use mainframes to process information about millions of policyholders.

UTILITIES

perform specific tasks related to managing computer resources. One of the most essential utility programs that every computer system should have is an antivirus program.

RTOS

real time operating system, for mobile devices

Information system

several parts: people, procedures, software, hardware, data, and the Internet.

Types of Computers

supercomputers, mainframe computers, midrange computers, and personal computers.

The Internet of Things (IoT)

the continuing development of the Internet that allows everyday objects embedded with electronic devices to send and receive data over the Internet. It promises to connect all types of devices from computers to smartphones to watches to any number of everyday devices.

Supercomputers

the most powerful type of computer. These machines are special, high-capacity computers used by very large organizations. Supercomputers are typically used to process massive amounts of data. For example, they are used to analyze and predict worldwide weather patterns. IBM's Blue Gene supercomputer is one of the fastest computers in the world

Input/output

translate data and programs that humans can understand into a form that the computer can process. The most common input devices are the keyboard and the mouse. Output devices translate the processed information from the computer into a form that humans can understand. The most common output device is the display, also known as a monitor

Database files

typically created by database management programs to contain highly structured and organized data. For example, an employee database file might contain all the workers' names, Social Security numbers, job titles, and other related pieces of information.

Hard disks

typically used to store programs and very large data files. Using rigid metallic platters and read/write heads that move across the platters, data and information are stored using magnetic charges on the disk's surface. In contrast, solid-state storage does not have any moving parts, is more reliable, and requires less power. It saves data and information electronically similar to RAM except that it is not volatile. (See Figure 1-15.) Optical discs use laser technology to store data and programs. Three types of optical discs are compact discs (CDs), digital versatile (or video) discs (DVDs), and Blu-ray discs (BD).

Cloud computing

uses the Internet and the web to shift many computer activities from a user's computer to computers on the Internet. Rather than relying solely on their computer, users can now use the Internet to connect to the cloud and access more powerful computers, software, and storage.