Google calls it a cache. Since this thread is about the "Google 'Cache'," it's only reasonable to use Google's term
Google's term for this feature is wrong. It may well have been chosen some years ago in the hope of confusing people and making it sound more legitimate - boy were they right to choose that term or what?
The reason why I have made this point clear is that some people seem to think that the Google archive is no different to the cache on their ISP's server even their own computer. Clearly, the reason they believe this is because of the name Google have chosen to use for this feature.
It's also worth pointing out that the robots meta tag to disable this feature is noarchive.