The National Center for Biotechnology Information (NCBI) is a division of the U.S. National Library of Medicine (NLM), part of the National Institutes of Health (NIH). Established in 1988, NCBI's mission is to develop and maintain information systems for molecular biology, biotechnology, and biomedicine.

NCBI provides free and publicly accessible databases, tools, and resources that are critical for biological and biomedical research. Its most well-known services include:

PubMed – biomedical literature search engine.

GenBank – nucleotide sequence database.

PubMed Central (PMC) – free full-text repository of biomedical articles.

BLAST (Basic Local Alignment Search Tool) – for comparing genetic sequences.

Gene, SNP, OMIM, dbGaP – databases for gene function, variation, and genetic association studies.

Website: https://www.ncbi.nlm.nih.gov