All professors have different expectations about the length and contents of annotations. Be sure to check the assignment sheet or ask your professor what they require for your annotated bibliography.
A reference list is a list of citations to books, articles, and other sources used while researching a topic. Reference lists may also be called "Bibliographies" or "Works Cited," depending on the style manual used.
An annotation is a summary or evaluation.
An annotated bibliography is a reference list/bibliography with annotations for the items cited.
Descriptive annotations focus on describing the cited items and may include information such as: