Computer servers, computer networks, to other computers and have their functions and services, such as providing it. In addition, such software. Is also indicated by the abbreviations such as “”SV”” and “”srv””, “”svr””. If the point explicitly to the computer (the hardware) it is called “”Server computer””, “”machine””, “”server machine”” and refers to the software called “”software”” and “”server software”” server program. In addition, Crown type, such as features, such as “”database server””, “”Web server””, “”00″” and called General. On the other hand, accesses the server over the network, or receive other functions and services, such as you can use computer and software called client (client). Connect to the host (host), the host software running on computer body responsible for actual processing in the field, such as the so-called large general-purpose machines (main frame), and the data input and output devices and software is called Terminal (terminal).