Caching

Caching means storing data in a temporary space (a cache) so that it can be retrieved faster in subsequent requests. The temporary space can be application memory, server hard disk space, or something else. The whole purpose of caching is to lighten the workload by avoiding any heavy processes for querying the data again. For example, in our Smilecook application, if we reckon that the recipes from a popular author will always get queried by the users, we can cache these recipes. So, the next time that users ask for these recipes, we can just send back the recipes in the cache instead of querying against our database. You can see caching everywhere. Almost all applications have caching implemented nowadays. Even in our local browsers, we save website results on the local hard disk to achieve faster access next time.

For server-level caching, most of the time, the cache is stored in the same web server as the application. But technically speaking, it can be stored in another...