The document discusses how Redis can be used and its benefits. Redis is an open source, BSD licensed key-value store that can be used as an advanced data structure server since keys can contain strings, hashes, lists, sets and sorted sets. It describes how Redis is very fast, useful for caching, and commonly used by large companies like Twitter, Pinterest, Wikipedia and others to power their infrastructure. Examples of how Redis is used include storing user timelines and profiles, caching query results, and as a message broker for pub/sub features.