The template modules options in the user interface represent a simple and flexible way to achieve the vast majority of caching scenarios. However, in the event that you need even more control over how and when things get cached, you can explore a whole new set of arguments added to the tag. For example, suppose you have a template module that is shared across a number of different templates. And suppose the output from that template module will vary greatly depending upon the template in which it is used. Therefore a simple global cache for that module is inadequate. The key argument in the tag will allow you to specify a lookup key for the cached content that is specific to the context in which it is used, thus allowing a single template module to cache 5 or more different versions of itself.
