In this course weâ€™re going to take a look at Redis. Redis isnâ€™t exactly a database: itâ€™s not relational or document-oriented. Instead, itâ€™s a key-value storeâ€”every â€œrecordâ€ is just label and a piece of data. That might sound boring, but I think youâ€™ll find that Redis has a lot to offer.
Key-Value store is a storage system where data is stored in form of key and value pairs. When we say in-memory key-value store, by that we mean that the key-value pairs are stored in primary memory(RAM). So we can say that Redis stored data in RAM in form of key-value pairs.
Redis is used by many large websites to inplement caching on their backend.