Many definitions are possible, but in this course a computer is defined as a machine that accepts data as input, processes data without human intervention by using stored instructions, and outputs information. The instructions, also called a program, are step-by-step directions for performing a specific task, written in a language the computer can understand. Remember that a computer only processes data (raw facts); it cannot change or correct the data that is entered. If data is erroneous, the information the computer provides is also erroneous. This rule is sometimes called GIGO: garbage in, garbage out.
To write a computer program, first you must know what needs to be done, and then you must plan a method to achieve this goal, including selecting the right language for the task. Many computer languages are available; the language you select depends on the problem being solved and the type of computer you are using. Regardless of the language, a program is also referred to as the source code.
A computer system consists of hardware and software. Hardware components are physical devices, such as key-boards, monitors, and processing units. The software component consists of programs written in computer languages. Input devices, such as keyboards, are used to send data and information to the computer. Output devices, such as monitors and printers, display the output a computer generates. Main (primary) memory is where computers store data and instructions, similar to a human brain. The central processing unit (CPU) is the heart of a computer.
Some computers have a single processor; other computers, called multiprocessors, contain multiple processors. Multiprocessing is the use of two or more CPUs in a single computer system. Generally, a multiprocessor computer performs better than a single-processor computer in the same way that a team would perform better than an individual on a large, time-consuming project.
30 сен 2024
