系统之间并不是孤立的,它们利用网络进行通讯连接到一起,从一个单独的系统来看,网络可以视为一个I/O设备,当系统复制一串字节到网络适配器时,数据流经过网络到达另外一台机器,而不是到达本地磁盘驱动器. 相似的,系统可以读取从其他机器发送来的数据,并把数据复制到自己的主存. 基于网络复制信息的功能,从一台主机复制信息到另外一台主机是计算机系统最重要的用途之一.
The system is not isolated, they use network communication and connected together. From a separate system, network can considereda I/O device, when the system copy a sequence bytes arrived the network adapter, data flow passed network and arrived another machinee, rather than local disk drive. Similary, system can read data send from another machine and copy data in itself main memory. Base the network copy information function, copy information for a machine arrived another machine is one of the best important application.