In computer science, a keyword is an identifier which indicates a specific command, and in most circumstances, has been reserved for core language usage. Some common keywords in many programming languages are: else, end, goto, if, print, return, switch, then, while, etc. There are usually restrictions about reusing keywords as names for user-defined objects such as variables or procedures, however some languages are extremely liberal in this approach (such as PostScript), allowing core keywords to be redefined for specific purposes. Languages vary as to what is provided as a keyword and what is a library routine, for example some languages provide keywords for input/output operations whereas in others these are library routines.
A keyword is a featured word of a technical article. Some publications specify a fixed set of keywords from which those for a particular article should be chosen.
Keywords are a feature of the ISPAmerica Online; which allow one to bypass URLs.