Computer system 

 System  is a group of elements that are related and work together. The computer system is an important component three parts.

Hardware

Software 

Personnel 

Hardware (Hardware) refers to the various devices as PC. Divided into the following components .

The data. Processing unit, a display unit .

1 . The data (Input unit) is a device input. To receive applications and data into computer. Input devices used are mostly the keyboard (Keyboard) and mouse (Mouse) There is also a device to another , including a scanner (Scanner), Video Cameron 's (Video Camera), microphone (Microphone. ) , touch screen (Touch screen), trackball (Trackball), digital cross- browser table and Share (Digiter tablet and crosshair).

Two . Processor (Central Processing Unit) , generally referred to as the CPU is the brains of the computer system. There are two key components of the control unit is calculated.

Control unit (Control Unit or CU) controls the sequence of the data display logic calculating unit . Memory and command interpreter .

Arithmetic and logic unit (Arithmetic and Logic Unit , or ALU) function to calculate the numbers , such as addition, subtraction, comparison

Memory is used to store programs and data used in the processing.

Three . Internal memory (Primary Storage Section or Memory) is memory within the computer to communicate with other agencies directly divided into two types.

Internal memory

- Memory RAM (Random Access Memory or Ram) is temporary memory . Used to store programs that are running at that time. Storage capacity of not more than 640 KB , the user is able to write or deleted at any time. If the computer is off or power failure. Will result in loss of data stored on it. And can not be restored .

- Memory ROM (Read Only Memory or Rom) is a memory forever. Can be read -only. Can not save data. Although the shutdown or power failure. Stored data will remain.

            Two . Secondary storage , including magnetic tapes, magnetic disks (Diskett) CD-ROM.

Disc or blades . A small, flexible magnetic disk storage using magnetic power . Applications will need to use the Disk Drive is a device that drives the disc. By dividing the surface into position . Tracks and sectors is divided into three dimensions .

8-inch disks currently used.

Disc 5.25 inch DD is divided into three approximately 360 KB of data and can record HD has 1.2 MB.

3.5-inch disk into DD can save approximately 720 KB and 1.44 MB HD can record more common nowadays .

ขนาด 5.25 นิ้ว                                 ขนาด 1.44 MB                                            

5.25 inch 1.44 MB.

Measured the capacity of the data on the computer .

  8 Bit.

1 Byte.

1 Byte 1 value.

1 KB 1,024 Byte.

1 MB 1,024 KB.

1 GB 1,024 MB.

1 TB 1,024 GB.

    Memory is the lowest bit (BIT [Binary Digit]) by using bits instead of one character or one byte (Bite) larger unit to another unit is KB (Kilobyte) where 1 kilobyte is equal to 2 10 . bytes or 1,024 bytes of memory, up to a megabyte gigabyte and terabyte .

HDD (Hard Disk) , a rigid magnetic disk . With fixed no movement . Can contain as many as 2 sizes .

                First . 5.25 inches (now deprecated) .

             Two . 3.5 inch .

            The two dimensions have a capacity ranging from 10,20,40,80,120,300,400 MB1 GB, 2 GB , etc used from 10 GB or more.

 Hard disk.

Data Rate refers to the speed of reading data from the disk to the computer's brain . (Or the speed of the machine to record information from the brain to the disc ) is measured . Number of bytes per second (Bytes Per Second , or bps).

CD -ROM (CD-Rom) is a type of optical disc . Storage with high- speed applications .

                        The following features.

A medium that can store a lot. It has a capacity of up to 2 GB (2 billion bytes ) .

Small portable convenience .

Use of laser technology to read and write data.

Fast Light is readonly (Read Only Memory) can not write or delete data.

                                CD - ROM.

Three . Displays (Output Unit) serves to show the results of the processing of computer. Or the results to be used later , including monitor (Monitor) output device is the printer (Printer).

Software (Software) is defined as the set of instructions written for a computer to follow the two types.

System software (System Software) is a set of instructions , or programs that control the computer . Mediate between applications on your computer. To assist in the management of computer resources, including the driver . Operating systems such as DOS, Windows, Os / 2, Unix.

Software application (Application Software) is a set of instructions or programs written to work as a computer user wants to include various software packages .

        Personnel  refers to computer personnel who served in the use and care , such as computer programmers (Programmer) , systems analysts (System Analyst) etc.