Both of these products provide access to MEDLINE. PubMed is a database containing MEDLINE, PreMEDLINE (citations provided to the database from publishers before the citations are edited and subject headings are added), and other literature citations created and produced by the National Library of Medicine.

Ovid Technologies provides separate software for searching a variety of databases including MEDLINE, PreMEDLINE, EBM (Evidence Based Medicine) Reviews, Cochrane Database of Systematic Reviews (literature reviewed for excellence in research methodology), Cancerlit, CINAHL (Cumulated Index to Nursing and Allied Health Literature), and EMBASE (Excerpta Medica Database, a major biomedical and pharmaceutical database well known for its international scope). Ovid's interface allows one to run the same search across multiple databases. This feature enhances the results by taking advantage of the unique focus of these various databases.

Advantages and limitations exist for both PubMed and Ovid interfaces. Classes and consultations are provided by librarians, in order to use these resources to your best advantage.