A programmable machine that performs high-speed processing of numbers, as well as of text, graphics, symbols, and sound. All computers contain a central processing unit that interprets and executes instructions; input devices, such as a keyboard and a mouse, through which data and commands enter the computer; memory that enables the computer to store programs and data; and output devices, such as printers and display screens, that show the results after the computer has processed data.
A device used for computing and otherwise processing information; specif., an electronic machine which, by means of stored instructions and information, is used to perform rapid, often complex calculations, compile and correlate data, download and play audio and video communications, access the World Wide Web, send and receive e-mail, etc.; now, esp., digital computer. The definition of a computer is a person or electronic device that makes and stores quick calculations or processes information. An example of a famous human computer is Ada Lovelace. An example of a computer is the MacBook.
A machine that computes. Specifically, a modern computer is a digital electronic system that performs complex calculations or compiles, correlates, or otherwise processes data based on instructions in the form of stored programs and input data.A device that can receive, store, retrieve, process, and output data. A programmable machine that responds to specified instructions and can execute a list of instructions known as a program. Today’s computers are electronic and digital—with wires, transistors, and circuits comprising the hardware and instructions and data comprising the software. Computers generally have these hardware components: (1) memory, allowing a computer to store data and programs, at least temporarily; (2) mass storage devices, allowing a computer to store and retain large amounts of data on the disk drives and tape drives; (3) input devices such as keyboards and a mouse, which act as conduits through which data are entered into a computer; (4) output devices, such as display screens and printers, that let users see what the computer has performed; and (5) a CPU or central processing unit, the primary component that executes the commands or instructions. On a humorous note, in a New Scientist article, futurologist Ray Kurzwell said that although a $1,000 personal computer in 2005 has about the computing power equivalent to that of an insect brain, if development advances continue at the same rate into the future, within 15 years a $1,000 personal computer should have the computing power equivalent to that of a human brain. On a global note, a controversial “computer-political” case arose on March 8, 2005, when Japan’s anti-monopoly agency demanded that Intel Corporation stop business practices that the agency alleged were giving the world’s dominant CPU chip maker an unfair advantage in the PC marketplace. Japan’s Fair Trade Commission (FTC) maintained that it would put forth a motion to enforce harsh actions if Intel failed to respond within 10 days to the allegations. In particular, the FTC claimed that Intel was in breach of Japan’s antitrust laws as early as 2002 when the company gave discounts and marketing payments to PC manufacturers in exchange for exclusivity or near-exclusivity. The FTC claimed that Intel was engaging in actions to keep the CPUs made by competing companies from being used—thus resulting in the limited marketing success of Japan’s own CPU chip manufacturers. Intel’s marketshare of the CPU market in Japan rose to 90% in 2004 from 78% in 2002. The FTC alleged that Intel had offered special incentives to Hitachi Ltd., Sony Corporation, Fujitsu Ltd., Toshiba Corporation, and NEC Corporation to use the Intel chip and the branding of “Intel Inside” or “Centrino” (Intel’s wireless networking chipset). Intel defended its business practices as being not only fair but also lawful. Associated Press. Microchips: Japanese Watchdog says Intel Practices Illegal. The Globe and Mail, March 9, 2005, p. B12; Kesterton, M. Upgrade Your System? The Globe and Mail, May 6, 2005. Such a device along with peripherals, especially a monitor, keyboard, and mouse. A device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information.
Program: A computer Program is a set of related instructions written in the language of the computer & is used to make the computer perform a specific task (or, to direct the computer on what to do). A set of related instructions which specify how the data is to be processed. A set of instructions used to guide a computer through a process.Data: Is a collection of raw facts, figures or instructions that do not have much meaning to the user. Data may be in form of numbers, alphabets/letters or symbols, and can be processed to produce information.TYPES OF DATA. There are two types/forms of data:a). Digital (discrete) data: Digital data is discrete in nature. It must be represented in form of numbers, alphabets or symbols for it to be processed by a computer. Digital data is obtained by counting. E.g. 1, 2, 3 …b). Analogue (continuous) data: Analogue data is continuous in nature. It must be represented in physical nature in order to be processed by the computer. Analogue data is obtained by measurement. E.g. Pressure, Temperature, Humidity, Lengths or currents, etc. The output is in form of smooth graphs from which the data can be read.Data Processing: It is the process of collecting all items of data together & converting them into information.Processing refers to the way the data is manipulated (or handled) to turn it into information. The processing may involve calculation, comparison or any other logic to produce the required result. The processing of the data usually results in some meaningful information being produced.Information: is the data which has been refined, summarized & manipulated in the way you want it, or into a more meaningful form for decision-making. The information must be accurate, timely, complete and relevant. Characteristics / Features of a Computer. Before 20th century, most information was processed manually or by use of simple machines. Today, millions of people are using computers in offices and at home to produce and store all types of information The following are some of the attributes that make computers widely accepted & used in the day-to-day activities in our society: 1. Speed. Computers operate at very high speeds, and can perform very many functions within a very short time. They can perform a much complicated task much faster than a human being. The speed of a computer is measured in Fractions of seconds. Millisecond - a thousandth of a second (10-3) Microsecond - a millionth of a second (10-6) Nanosecond - a thousand millionth of a second (10-9) Picosecond - a million millionth of a second (10-12) The speed of a computer is usually linked to the technology used to build it. a). 1st Generation computers (1940s & early 1950s). • The computers were built using Vacuum tubes, and the speed was measured in Milliseconds. E.g., a computer could perform 5,000 additions & 300 multiplications per second.
CLASSIFICATION OF COMPUTERS Computer exist in defferent sizes, weight and shapes The major ways in which computers are classified are i) Classification according to Functionality In this category, computers are categorised ccording to the way they process data and kind of data a computer can process. Example of this data are, a) Analog Data b) Digital data ii) Classification according to the purpose iii) Classification according to physical size iii) classification according to functionality ACCORDING TO PHYSICAL SIZETYPES OF COMPUTER Analog computer Analog computer measures and answer the questions by the method of “HOW MUCH”. The input data is not a number infect a physical quantity like temp, pressure, speed, velocity.
Time is wasted in transmission time ANALOG COMPUTER
DIGITAL COMPUTERS Digital computer counts and answer the questions by the method of “HOW Many”. The input data is represented by a number. These are used for the logical and arithmetic operations.
MICRO COMPUTERS Micro computer are the smallest computer system. There size range from calculator to desktop size. Its CPU is microprocessor. It also known as Grand child Computer.
MINI COMPUTERS These are also small general purpose system. They are generally more powerful and most useful as compared to micro computer. Mini computer are also known as mid range computer or Child computer.
MAINFRAME COMPUTERS Mainframe computers are those computers that offer faster processing and grater storage area. The word “main frame” comes from the metal frames. It is also known as Father computer.
SUPER COMPUTERS
CLASSIFICATION OF DIGITAL COMPUTERS
WORKSTATION TABLET PC HANDHELD PC (PDA) SMART PHONE |