System Unit

RAM

• is a form of computer data storage.
• Pronounced ramm, acronym for random access memory 
• a type of computer can be accessed randomly
• byte of memory can be accessed without preceding bytes.
• found in computer or other devices, such as printers.

Cache Memory

• the cache is a small amount of high speed memory, usually with a memory cycle comparable to the time required by the CPU fetch one instruction.
• is a components that transparently stores data so that future data for the requests can be served faster.
• duplicates of original values that are stored elsewhere.
• request where is contained in the cache can be served by simply reading the cache that is comparatively faster.
• caches have proven themselves in accessing patterns of typical computer applications have locality of reference.

Flash Memory

• Is a non-volatile computer storage chip that can be electronically erased and reprogrammed.
• used in memory cards, USB flash drives, MP3 players and solid state drivers for general storage and transfer of data between computers and other digital products.
• offers fast read access times and better kinetic shock resistance than hard disks.
• 2 different technologies - NOR and NAND -- to map data. NOR flash provides high speed random access, reading and writing data in specific memory locations. NAND flash reads and writes sequentially at high speed, handling data in small blocks called pages and quickly transferring whole pages of data. 

Graphic Cards

• is an expansion whose function is to generate output images to a display.
• offer added functions, such as accelerated rendering 3D scenes or 2D graphics, video capture, TV tuner adapter, MPEG-2/ MPEG-4 decoding, Firewire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor).

Sound Card

• Is an internal computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. 
• applied to external audio interfaces that use to generate sound, as opposed to using hardware inside the PC.
• Providing audio components for multimedia applications such as music composition, editing video, presentation, education and entertainment(games) and video projection.

Network Interface Card

• is also known as network interface controller, network adapter, LAN adapter
• is a computer hardware component that connects a computer to a computer network.
• implemented on expansion cards that plug into a computer bus, the low cost and ubiquity of the Ethernet standard means that most newer computers have a network interface built ionto the motherboard.

Plug & Play

• a term used to describe the characteristic of a computer bus, or device specification, which facilitates the discovery of a hardware component in a system.

• refers to both the booth-time assignment of device resources, and hotplug systems such as USB and Firewire.

Serial Port

• is a serial communication physical interface through which information transfers in or out one bit at a time( contrast parallel port).
• Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals and various peripherals.
• indentifiess hardware more or less complaint to the RS-232 standard, intended to interface with a modem or with a similar communication device.

Parallel Port

• is a type of interface found on computers (personal and otherwise) for connecting various peripherals.
• is a parallel communication physical interface.
• is also known as a printer port or centronics port.
•  IEEE 1284 standard defines the bi-directional version of port, which allows the transmission and reception of data bits at the same time.

Universal Serial bus Port

• is a specification to establish communication between devices and a host controller (usually a personal computer), which has effectively replaced a variety of earlirer interfaces such as serial and parallel ports.
• can connect computer peripherals such as mice, keyborads, digital cameras, printers, personal media players, flash drives, Network Adapters, and external hard drives.

Firewire port

• is a serial computer port that uses Firewire technology to transfer data rapidly from one electronic device to another.
• has the ability to interact with a number of different devices.
• Fireware connection can provide an ideal way to connect a scanner to a computer system.

Ethernet port

• is an opening on computer network equipment that Ethernet cables plug into, those are alternatively called jacks or sockets.
• is a family of frame-based computer networking technologies for local area networks(LAN).
• defines a number of wiring and signaling standards for the physiacl layer of the standard networking model.
• connecting the device to a wired network.

High Definition Multimedia Interface

• HDMI is a compact audio/ video interface for trasmitting uncompressed digital data.
• is a digital alternative to consumer analog standards, such a radio frequency (RF) coaxial cable, composite video, S-video, SCART, component video, D-terminal, or VGA.
• connects digital audio/video sources and compatible digital devices, computer monitors, video projectors, and digital televisions.