PubMed is a free resource developed by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM). The PubMed database inlcudes over 26 million citations to biomedical literature from MEDLINE, life sciences journals, citations to articles published by NIH funded researchers, and citations to books, including some book chapters. Content dates back to 1946 and is updated 6 days a week.
Most PubMed records are MEDLINE citations. MEDLINE is the National Library of Medicine’s premier bibliographic database containing citations and author abstracts from more than 5,600 biomedical journals published in the United States and in other countries.
PubMed Central (PMC) is a free archive of full text articles from biomedical and life sciences journals. It includes articles from publicly funded research, including NIH, AHRQ, CDC, FDA, NASA, and the VA. A requirement of publicly funded research is to provide full text articles for free to the public.