OpenAFS is a distributed filesystem product offering a client-server architecture for file sharing, providing location independence, scalability and transparent migration capabilities for data.

AFS is a distributed filesystem product, pioneered at Carnegie Mellon University and supported and developed as a product by Transarc Corporation (now IBM Pittsburgh Labs). It offers a client-server architecture for file sharing, providing location independence, scalability and transparent migration capabilities for data.
IBM branched the source of the AFS product, and made a copy of the source available for community development and maintenance. They called the release OpenAFS.