An abstract is a descriptive summary of an article you read.
An annotattion is a descriptive AND critical summary of an article you read. Some of the following criteria can be used to think critically about what you read:
What is a literature review?
The purpose of a literature review is to provide for the reader an up to date overview of what is known about a particular topic. The term "literature" refers to the published works (articles and books) on a given topic. A literature review typically includes:
A literature review is more than a descriptive summary of each of the articles or books that you find. A literature review is also a synthesis. To synthesize is to combine the ideas that you find in the literature to identify general trends, key arguments, controversies or issues.