Redis

(From https://try.redis.io/)

Redis is in the family of databases called key-value stores.

The essence of a key-value store is the ability to store some data, called a value, inside a key. This data can later be retrieved only if we know the exact key used to store it.

Often Redis it is called a data structure server because it has outer key-value shell, but each value can contain a complex data structure, such as a string, a list, a hashes, or ordered data structures called sorted sets as well as probabilistic data structures like hyperloglog.

https://blog.csdn.net/sinat_34496643/article/details/80077319#:~:text=Redis%E6%98%AF%E4%B8%80%E7%A7%8D%E5%9F%BA%E4%BA%8E,%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E5%92%8C%E7%AE%97%E6%B3%95%E7%BB%84%E6%88%90%E3%80%82