The Entrez Global Query Cross-Database Search System is a powerful feerated search engine, or web portal that allows users to search many discrete health sciences databases at the National Center for Biotechnology Information (NCBI) website. NCBI is part of the National Library of Medicine (NLM), itself a department of the National Institutes of Health (NIH) of the United States government. Entrez also happens to be the French second person plural (or formal) form of the verb "to enter", meaning literally "come in".