Terms for documentation is a great thing to think about. Thanks for mentioning it. The terms are not the same I think; and the vantage point is completely different.

From a users vantage I think most look at this from the perspective of the things they want cached... the cacheable. We'd definitely want a good term for that. Cacheable has a nice tie in terms of JPA's @Cacheable which most users would already understand.

And we'd need to be able to properly explain "region", especially:

1. How that ties to the cache provider in terms of config, etc
2. How Cacheable relates to Region