PACS, picture archiving and communication systems, is a term used for a set of computers connected by a network, and dedicated to the storage, retrieval, distribution, and presentation of medical images. A PACS is independent of the format of the information.

Some vendors use the term VNA (Vendor Neutral Archive), but in most respects, the terms are synonymous.

The Digital Imaging and Communications in Medicine (DICOM) standard format is the most common format for medical image data found in PACS.