Distributed file systems (DFS)

Broadly and informally defined, distributed file systems are systems which allow to store data by sharing it across many network-connected computers. Distributed file system allows files to be accessed using the same interfaces and semantics as local files – for example, mounting/unmounting, listing directories, read/write at byte boundaries, system's native permission model (says Wikipedia).

DFS is not a new technology -- it predates the Internet. But combined with Internet, consensus protocols and modern cryptographic technology they offer new and exciting possibilities.