PubMed is an index of the biomedical literature. A PMID, also known as the PubMed reference number, is a number assigned by the NIH National Library of Medicine to papers indexed in PubMed.
PubMed Central is an archive of full-text journal articles. The National Library of Medicine assigns a PMCID, also known as a PMC Identifier, to each full-text paper in PubMed Central. PMCID numbers also appear in PubMed records. See sample below.
Below is a record from PubMed which includes both a PMID and a PMCID.
