Redis is an open-source, networked, in-memory, key-value data store with optional durability. It is written in ANSI C. The development of Redis is sponsored by Redis Labs today; before that, it was sponsored by Pivotal and VMware. According to the monthly ranking by DB-Engines.com, Redis is the most popular key-value store. The name Redis means REmote DIctionary Server.
For the ease of accessing Redis from other containers via Docker networking, the "Protected mode" is turned off by default. This means that if you expose the port outside of your host (e.g., via -p on docker run), it will be open without a password to anyone. It is highly recommended to set a password (by supplying a config file) if you plan on exposing your Redis instance to the internet. For further information, see the following links about Redis security: