Review articles cover a particular subject or facet of a subject in depth and in detail. They are normally written by experts in a particular field, and may be cited frequently in other articles, forming a base line in the academic dialogue in a given area. They are a place to start if you are beginning to study a field, to discover facets that you may have missed or misunderstood, or if you need an overview.
The definition of what constitutes a review article may vary from field to field. The best idea is to examine several to get an idea of what is normally included; then you'll have a basis of comparison. The "Annual Review" series is one place to start.
The databases may tag review articles so that you can find them that way.
However, review articles are NOT book reviews, product reviews, or the like. They are also not usually considered bibliographies, although a review article may contain a bibliography; they will almost certainly have a lengthy list of references.