System Unit

Expansion Card

Expansion card is known as an electronic card with the ability to connect to the other computer. that can be installed in computer to add functionality to it such as PCI slots. Expansion cards are installed into the expansion slot of a computer motherboard. They enhance the computer’s ability to perform additional functions not offered by the motherboard. Video cards and sound cards are common examples of PC expansion cards.

Network Interface Card


A network interface card is used to connect a computer to an Ethernet network. It provides an interface to the media. The card usually also contains the protocol control firmware and Ethernet Controller needed to support the Medium Access Control (MAC) data link protocol used by Ethernet. A unique 48-bit serial number is being contained by the Ethernet which is known as MAC address, it is stored in ROM carried on the card. It iscompulsory for every computer on an Ethernet network must have a card with a unique MAC address.

Cache Memory
A memory cache, sometimes called a cache store or RAM cache, is a portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory. Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.

Plug and play

Plug and Play, sometimes, abbreviated PnP, is a catchy phrase used to describe devices that work with a computer system as soon as they are connected. The user does not have to manually install drivers for the device or even tell the computer that a new device has been added. Instead the computer automatically recognizes the device, loads new drivers for the hardware if needed, and begins to work with the newly connected device.

Socket





A computer program needs to connect to a local or wide area network such as the Internet, it uses a software component called a socket. It opens the network connection for the program, allowing data to be read and written over the network. It is important to note that these sockets are software, not hardware, like a wall socket. Sockets are a key part of Unix and Windows-based operating systems. They make it easy for software developers to create network-enabled programs.


Chips

A small piece of semiconducting material (usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components (transistors). Computers consist of many chips placed on electronic boards called printed circuit boards.
There are different types of chips. For example, CPU chips (also called microprocessors) contain an entire processing unit, whereas memory chips contain blank memory.

Slots



An opening in a computer where you can insert a printed circuit board. Slots are often called expansion slots because they allow you to expand the capabilities of a computer. The boards you insert in expansion slots are called expansion boards or add-on boards. Slots are different from BaysBays are sites within the computer where you can install disk drives. Typically, slots are in the back of the computer and bays are in the front.


Bus lines


The bus lines are the communicating electronic lines that connect different parts of the CPU to various other parts. In addition, the bus lines also link the CPU to different parts on the system board of your computer. The data flows in the form of bits along the bus lines. The bus lines are like multilane pathway which means that the more bus lines are on the system the greater is the rate of transfer of data along the bus, which means that the computer can run efficiently and will perform the operations at a faster rate.



Serial port



An Asynchronous port on the computer used to connect a serial device to the computer and capable of transmitting one bit at a time. Serial ports are typically identified on IBM compatible computers as COM (communications) ports. For example, a mouse might be connected to COM1 and a modem to COM2. With the introduction of USB, FireWire, and other faster solutions serial ports are rarely used when compared to how often they've been used in the past. To the right is a close up of a DB9 serial port on the back of a computer.

Parallel Port







A parallel interface for connecting an external device such as a printer. Most personal computers have both a parallel port and at least one serial port. A newer type of parallel port, which supports the same connectors as the Centronics interface, is the EPP (Enhanced Parallel Port) or ECP (Extended Capabilities Port). Both of these parallel ports support bi-directional communication and transfer rates ten times as fast as the Centronics port.
Macintoshes have a SCSI port, which is parallel, but more flexible.


Universal Serial Bus


Universal Serial Bus (USB) is a set of connectivity specifications developed by Intel in collaboration with industry leaders. USB allows high-speed, easy connection of peripherals to a PC. When plugged in, everything configures automatically. USB is the most successful interconnect in the history of personal computing and has migrated into consumer electronics (CE) and mobile products.

Firewire Port




A high-speed serial bus that was developed by Apple, Texas Instruments and others via the IEEE. Standardized as the IEEE 1394 High Performance Serial Bus (HPSB), FireWire supports 63 devices, real-time data transfer, hot swapping and simultaneous multiple speeds. It is widely used to download video from digital camcorders to the computer and is also used in other A/V applications.