a computer on the Internet that has a large collection of files and programs, copied from other computers around the Internet, that a user can download
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。
personal digital assistant: a very small computer on which you could store personal information, write documents etc. They were mostly replaced by smartphones. 个人数字助理,掌上电脑(大多被智能手机所取代)
a server that is suitable to use for doing business over the Internet because it can deal with information that has been encrypted (=made safe by putting it into a form that not everyone can read)
a mobile computing device, larger than a mobile phone, that can browse the internet, handle email, play music and video, and display e-books. The user controls it by touching the screen.