Need access to primary structural data on biological macromolecules? This article describes the Protein Data Bank (PDB), the central worldwide archive for such information. The PDB serves as the primary source for a myriad of secondary databases and is the starting point for many structural bioinformatics investigations. The article explains the PDB's objectives, its data deposition and access procedures, and provides instructions for obtaining further details. Readers will gain a comprehensive understanding of the PDB's extent and the valuable resources it offers to the scientific community. Future developments are also discussed, underscoring the PDB's commitment to evolving as an essential tool for researchers worldwide. The resource provides biological macromolecules to scientists globally.