The document discusses using Redis as a data structure store and server. It introduces the main Redis data types - strings, hashes, lists, sets, and sorted sets. It provides examples of how to store common data types like pages, counts, users, and posts in each Redis data type. It also shows examples of Redis commands to store, retrieve, and manipulate data. Finally, it demonstrates some use cases for Redis including caching data, tracking online users, building leaderboards, and enabling cross-app communication.