A citation is made of parts, each part indicating specific information about the source (author, title, page no., etc. - depending on the resource). This bibliographic information together makes up a complete full citation.
A full citation will give the reader a clue as to the type of resource being described (chapter in a book, electronic journal article, thesis, etc.)
A reference list or list of cited works at the end of a paper is sometimes called a 'Bibliography' because it provides bibliographic information.