Essentially, an annotated bibliography is a bibliography that delivers a summary of each of the entries (references), the purpose of which is to provide the reader with a brief overview and an evaluation of each source. It can therefore be inferred that an annotated bibliography extends beyond what a regular bibliography (or reference list) includes. It is important to note the difference between annotations and abstracts. Abstracts are descriptive summaries that are typically found at the beginning of scholarly journal articles. On the other hand, annotations are not only descriptive, but also critical as they may describe an author's point of view, authority, or clarity and appropriateness of expression.
Regarding the manner in which to address those annotations, you should probably focus on the main information that you used from a particular source (such as a website), which would involve highlighting (although not in too much detail) the main elements that contributed to your depth study from said source. If your use of a particular source was extensive, that is, if you used a substantial amount of information from one source, you could write an annotation that describes the purpose of that source from a less specific and more general perspective.
I hope this helps!