URL-- Uniform Resource Locator

...a networked extension of the standard filename concept according to the folks who developed Mosaic, the first modern web browser (more details)

Typical web site locators begin with http://www... which implies a web site whose name begins with www... and whose software is prepared to accept HyperText Transfer Proticol requests from browsers on the Internet.

Some sites will accept File Transfer Protocol requests. Their URLs start ftp://...

Even a personal computer's own hard disc can be referenced. It's files have long names, URLs which begin file://...

A URL like /groups/PlanningCommunication/ is considered a relative locator: it does not begin with http://... It is considered relative as in relatively close, as in search starting right here. These are convenient for links within our web site. /groups/PlanningCommunication/ links to the group folder for the Planning, Marketing, and Communications committee.

The expression Uniform Reference Locator may be replaced in the future by the expression URI-- Uniform Resource Identifiers (more details)