What is the difference between PubMed and PubMed Central (PMC)?
PubMed is a database that contains over 20 million citations and abstracts of articles from life science, medicine, veterinary medicine, and biotechnology journals. It includes some links to full text articles in PubMed Central and other locations. PubMed Central (PMC) is an online archive of over 1 million full-text articles that are provided for free to the public. Most articles have a corresponding citation in PubMed. PMC contains additional material, such as book reviews, that are considered out of scope for PubMed.