1. A bibliography is a list of details of sources of information.
2. An annotation is a short piece of writing (e.g. a paragraph) where you describe and evaluate a source of information. You use your own words in the annotation.
Sources of help
Some IAs require you to provide an annotated bibliography as part of your work.
Studyweb has a good list of tips about constructing an annotated bibliography (scroll down to the bottom of their page for the list), together with a good example.