现代计算机能在不断电的情况下连接或断开网络和外围设备，这意味着硬件的增加或消失都是正常的，打印机、调制解调器和文件服务器可以像潮水一样来去自由。

• Modern computers can be connected to and disconnected from networks and peripherals without having to first power down. This means that it is now normal for hardware to appear and disappear ad hoc. Printers, modems, and file servers can come and go like the tides.