Redis is an open-source (BSD licensed), in-memory data structure store. You can use it as a Memcached alternative to store simple key-value pairs. Moreover, you can use it as a NoSQL database or even a message broker with the Pub-Sub pattern. Redis is written in C programming language. The Redis project is developed and maintained by a project core team and, as of 2015, is sponsored by Redis Labs.
This tutorial will help you install the Redis server and PHP extensions on an Ubuntu 20.04 LTS system.