We have taken a look at the two caching technologies, Redis and Memcached that AWS provides in its ElastiCache service. We have also looked at the different ways these two technologies can be used to deliver an efficient caching store that can be used to offload database burdens, store session and other simple data type information, and also deliver an in-memory database that supports complex queries and data types. We have looked at the caching strategies that allow us to control our data in the cache and got an overview that will help us to choose the right solution for our data and what we need to be careful of when using caching. In the next chapter, we will look into Amazon DynamoDB which is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability.