The cache system requires a small amount of setup. Namely, you have to tell it where your cached data should live; whether in a database, on the filesystem or directly in memory. This is an important decision that affects your cache's performance.
Your cache preference goes in the CACHES
setting in your settings file.
The fastest, most efficient type of cache supported natively by Django, Memcached (for more information visit http://memcached.org/) is an entirely memory-based cache server, originally developed to handle high loads at LiveJournal.com and subsequently open-sourced by Danga Interactive. It's used by sites such as Facebook and Wikipedia to reduce database access and dramatically increase site performance.
Memcached runs as a daemon and is allotted a specified amount of RAM. All it does is provide a fast interface for adding, retrieving and deleting data in the cache. All data is stored directly in memory, so there's no overhead of database or filesystem...