Server is a computer, it run faster than the ordinary computer, the load is higher, the price is more expensive, servers in the network for other clients (such as PC, smart phones, such as ATM terminal even train system and other large equipment) provide calculation or application service, the server has a high-speed CPU computing power, the reliable operation of the long, powerful I/O throughput capacity of external data and better extensibility, according to the services provided by the server, the server has generally assume response service request, undertake the service, the ability of security services, the server as electronic equipment, its internal structure is very complex, but the difference between internal structure with the ordinary computer, such as CPU, hard disk, memory, system, system bus, etc.,