Biography is a genre where the text is written about a person by another person. An autobiography, as the term suggests, is written by a person about her or himself. In the Library, these books are located in a relevant subject section, as a person may be famous for one thing or an event, or perhaps because of the job s/he did.
As well as these suggestions and recommendations, you can also look at the library catalogue here, where you can do a subject, search, using the words to describe these genres: biography and autobiography.