A sound card or audio board allows computers to play and record sound. If you have a 5.1 or 7.1 audio board, you can connect your computer to your home cinema set for the real cinema experience, with full surround sound, whilst playing games or viewing DVDs.
The graphics card, also known as the video card, is the complete graphical subsystem of the PC. It is responsible for the quality and speed of video processing. For users that wish to play games or work with multimedia applications, it is especially important to have a video board with a high performance graphics processor and enough memory.
The Random Access Memory (RAM) is an important part of computers, servers and other electronic devices. Generally it is much faster than the permanent storage memory of your device and all information stored in it will be lost when you switch off your device. Extra RAM is often an affordable and efficient way to upgrade your slightly outdated device, so you can use it another year.
The motherboard or mainboard is the component that connects all the different parts of your computer. Often it has some integrated components like a sound card, enabling your computer to play sound, or a network card, to connect your computer to the network. The standard form factor (size) for motherboards is ATX, you need at least a midi-tower to fit one of those in. Micro-ATX motherboards are often more complete and have more onboard devices, like a video board and fit in smaller cases, but are generally less expandable.
A NIC or Network Interface Card is a circuit board or chip which allows the computer to communicate to other computers on a network. When connected to the network, computers can share websites, files, printers and other resources. The most popular networking standard at the moment is Ethernet, which one can recognize by the rectangular connectors with eight wires in them. Wireless network with the 802.11b and the faster 802.11g standard is also increasingly popular, both at home and in the office, though it is not yet as fast as wired (ethernet) network. A public place where you can use wireless internet is called a "hot spot".
These run a peripheral device and are either contained on a plug-in expansion board or on the motherboard. In larger computers, a controller may be contained on one or more boards or in an external, stand-alone cabinet.
The Central Processing Unit (CPU) or (micro) processor is the part of a computer where most calculations take place. In terms of computing power, the processor is the most important element of a computer system, so the performance of a computer is highly dependant on the performance of the processor. For quite some time the performance of a processor has been determined by the number of MHz the clock speed was, but nowadays clock speed doesn't have so much to do with the speed of the processor anymore. One of the best ways to compare different kinds of processors, is to look up benchmarks on the internet. Please be careful to buy a processor that is compatible with your motherboard, i.e. fits in the right socket.
RAID is a storage technology that combines multiple disk drive components into a logical unit for the purposes of data redundancy and performance improvement. Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the specific level of redundancy and performance required. A RIAD controller, which is a type of disk array controller, is a device which manages the physical disk drives and presents them to the computer as logical units.
The motherboard is the main printed circuit board (PCB) in servers and computers. It holds many of the crucial electronic components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals.