Authentication

Authentication (pronounced "aw-then-ti-keyt") (from Greek "αυθεντικός;" real or genuine, from "authentes;" author) is the actions taken to establish or verify something (or someone) as "authentic". It is the method of verifying claims made by someone about the thing. This might involve confirming the identity of a person, the origins of an object (or something), or to make sure that a computer program (or user) is a trusted one. People are usually authenticated by something they know (password), something they have (key), or something they are (biometrics).