REDIS

REDIS: REmote DIctionary Server

used by Twitter, Pinterest, craigslist etc.

in-memory, multi-model database from 2009 (created by Salvatore Sanfilippo)

READ / WRITE quickly by using main computer memory

but stores data on disk, so can be reconstructed as needed, making the database durable, supporting snapshots and backups.

support for graphs, JSON documents, full-text search, and more.

sub-millisecond latency

Interact using SET and GET commands