C-book

Computers

An electronic device for analyzing and storing data, making calculations, etc.

Originates from the word compute which means calculate. Computers can be programmed to process data following some finite set of instructions.

Types of computers

Personal computers

Or PCs in short. Intended to be used by a single person. First introduced by IBM. Built around a family of microprocessors referred to as “8086” (manufactured by Intel). Therefore its structure is referred to as “x86 architecture”.

An alternate system was Macintosh (introduced by Apple). Due to differences in hardware architecture between x86 and Macintosh, software used by these systems were not portable to the other.

Network servers

Powerful personal computers with special hardware and software that enable them to function as primary computers in a network. They may be setup in groups called clusters or server farms.

Mainframe computers

Used in large organizations where many people, even thousands, frequently need to access the same data. Traditionally, each user accesses a mainframe computer through a device called a terminal.

Minicomputers

More powerful than personal computers but less powerful compared to mainframes. Aka. midrange computers.

Supercomputers

Most powerful, physically largest computers. Have thousands of processors.

Embedded computers

Computers that reside in a device and not directly visible. Aka. invisible computers. These devices are referred to as smart because they can interact with the environment in a more intelligent, adaptive, and efficient way.

Components of a computer system

A computer is a system. A complete computer system consists of:

• Hardware: Tangible elements that can be seen and touched
• Software: Programs that allow users to use the computer system and control its activities. Not tangible.
• Data: Individual facts or pieces of information that is input to the computer for processing or produces as output after processing.
• User(s)