An annotated bibliography gives an account of the research that has been done on a given topic. Like any bibliography (similar to a Reference List), an annotated bibliography is an alphabetical list of research sources. The differentiating feature of an annotated bibliography is that, in addition to the citation information, you must include a summary of each source and your view of its value or relevance.
Depending on your assignment, an annotated bibliography may be one stage in a larger research project, or it may be an independent project standing on its own.
For more information and samples on how to prepare an annotated bibliography, visit the Cornell University's Annotated Bibliography Guide.