a machine that storesprograms and information in electronic form and can be used for a variety of processes, for example writing, calculating, and communicating on the Internet 计算机;电脑
All our computers are linked to a main network. 我们的所有计算机都连接到一个主网上。
on/by computer:
Ticket reservations are all done on computer. 订票全是在计算机上完成的。