The document discusses several protein sequence databases including Swiss-Prot, GenPept/TREMBL, PIR, PDB, and MMDB. It provides details on Swiss-Prot, describing it as a manually curated database that distinguishes itself from others through annotations, minimal redundancy, and integration with other databases. The annotations in Swiss-Prot include core data as well as additional details on the protein's function, modifications, domains, structure, and relationships to other proteins and diseases.