PubMed is an online resource, a database service. It gives users a way to retrieve the collected information in a database, explains the University of Texas Libraries. The database that PubMed accesses is called MEDLINE.
MEDLINE was developed by The National Center for Biotechnology Information, a part of the National Library of Medicine. It is a database of abstracts and citations in the fields of medicine, dentistry, nursing, veterinary medicine, preclinical sciences and health care systems.
In addition to accessing MEDLINE, PubMed provides citations from a number of life science journals not included in the MEDLINE database. It can also access journal articles on other websites as well as the National Center for Biotechnology Information's molecular biology databases. Like MEDLINE, PubMed was developed by the NCBI at the NLM.
PubMed offers its users advanced search options and query filters to refine their searches. Along with the results, the service also displays related articles and "ads" for other data that might be of interest to the user.
MEDLINE's bibliographic database contains abstracts and citations from nearly 5,500 U.S. and worldwide biomedical journals, dating back to 1948. It holds citations to over 16 million articles and adds new ones at a rate of nearly 1 million articles a year.