Citation searching, also know as cited reference searching, is a search for other articles that have made reference to a particular book, article, or author. Citation searching will help you find similar research and find out how important a work is to your research.
A citation search will show you who has mentioned your article, where, and how many times. It will allow you to search forward in the published literature, starting from your known reference, to locate new articles which cite your known reference in their bibliographies.