The system unit

Flash memory

Flash memory refers to particular type of EEPROM, or Electronically Erasable Programmable that only read memory. It is a memory chip that maintains stored information without requiring a power source. It is often used in portable electronics, like MP3 players for songs, and in removable storage devices to save documents and files.

Graphics card

 Is a device installed in a computer that consists of a graphics processing unit designed to help process and show images, especially 3D graphics. Graphics cards help take the processing strain off the main processor, and can contain their own memory to take the strain off the system RAM.

Sound Card

An expansion board that makes the computer to manipulate and output sounds. Also sound cards are necessary for nearly all CD-ROMs and have become commonplace on modern personal computers. Sound cards enable the computer to output sound through speakers connected to the board, to record sound input from a microphone connected to the computer, and manipulate sound stored on a disk.



Network Interface Card (NTC)

Network Interface Card often abbreviated as NIC,it is  a board you insert into a computer so the computer can be connected to a network in the computer. Most NICs are designed for a particular type of network, protocol, and media, although some can serve multiple networks.

Plug and Play

In the world of computing,plug and play is a term used to describe the characteristic of a universal serial number, or device specification, which facilitates the discovery of a hardware component in a system, without the need for physical device configuration, or user intervention in resolving resource conflicts.Plug and play refers to both the boot-time assignment of device resources, and to hot plug systems such as USB and Firewire.

Busline

It is like a multi-lane pathway which allow the data to be transfered along the bus. It is the communicating electronic lines that connect different parts of the CPU to various other part

HDMI

HDMI (High Definition Multimedia Interface) is a specification that contain video and audio into a single digital interface for use with digital versatile disc (DVD) players, digital television (DTV) players, set-top boxes, and other audiovisual devices. 

Cache memory

Is an access memory that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory.