Storing frequently accessed data in a fast-access location to improve performance. Like keeping your most-used tools on your desk instead of walking to the toolbox each time.
Websites use caching to store images and files on your computer so they load instantly on repeat visits.
All provide managed in-memory caching (commonly Redis; AWS also supports Memcached) to reduce database load and speed up application responses. They differ mainly in supported engines, scaling options, and integrations with each cloud’s networking and monitoring.