The URI specification describes a resource as the common term for “…anything that has identity. Familiar examples include an electronic document, an image, a service (e.g., “today’s weather report for Los Angeles”), as well as a collection of other resources. Not all resources are network “retrievable”; e.g., human beings, corporations, and bound books in a library can also be considered resources…” (see also the term Web Resource).
Examples: Web page, collection of Web pages, service that provides information from a database, e-mail message, Java classes …