Often, students confuse a bibliography as being the same as a reference list. However, there is a key difference between the two and it is easy (once you've heard it) to know how they are different.
A reference list is attached at the end of a document, providing specific details of all works from which in-text references within the document have been made.
A bibliography also appears at the end of the document, after the reference list, and it lists specific details of all works consulted in the process of the compilation of a document, whether or not the work has been quoted from or referred to specifically within the document. It follows that all works which appeared in the reference list would also appear in the bibliography, but it is very likely that there would also be additional works listed in the bibliography, which may have been consulted in the research process without having been used for specific reference within the document.