The Protein Data Bank (PDB) is the single, freely available, global archive of structural data for biological macromolecules. It is maintained by the wwPDB consortium consisting of the Research Collaboratory for Structural Bioinformatics (RCSB PDB), the Protein Data Bank in Europe (PDBe), the PDB Japan (PDBj) and the BioMagResBank (BMRB). This chapter describes the organization of the wwPDB, the systems in place for data deposition, annotation and distribution, and a summary of the services provided by the wwPDB member sites.