A PC or personal computer, which is a multipurpose computer that can be used alone or connected to a network, and a server are alike in that they are made of hardware that runs software so that you can use them for work or play.
The server would be the central hub of a LAN or local area network and is usually used by a company to keep all of their software, documents, and files. The server does as its name suggests, it serves the network, and that is its only job. It should not be used as a workstation because it could compromise the information stored on the hard drive.