"Abstracts are the purely descriptive summaries often found at the beginning of scholarly journal articles or in periodical indexes. Annotations are descriptive and critical; they expose the author's point of view, clarity and appropriateness of expression, and authority." - Reference Department, Olin and Uris Libraries, Cornell University.
Links for writing abstracts and for annotated bibliography creation:
"An annotated bibliography is a list of citations to books, articles, and documents. Each citation is followed by a brief (usually about 150 words) descriptive and evaluative paragraph, the annotation. The purpose of the annotation is to inform the reader of the relevance, accuracy, and quality of the sources cited." - Reference Department, Olin and Uris Libraries, Cornell University.