When you do a search on Google, most, if not all, of the results have a cached link. The same for images.
I assume this to mean that Google has a copy of the site stored on their local servers from the most recent time they crawled it.
Which sorta makes sense. To be able to do a keyword search they have to have the entire text readily available.
Just how many millions of gigabytes does Google have in their data centers? And how much of the internet is stashed on them?