What happens when you click the "Cached Button" on Google for any website?

[melissa]

You know how there's a cached button on everything, well does it do anything to twitter? I mean like I wanted to click on a twitter page to see what that person twitted but I accidentally clicked the cached button... Does that lead to anything? Does it block all of the new tweets that person twitted? Or is it just that they didnt twittered in awhile?
The site is Twitter.
how do you know which version is cached?

[Thomas Mendez]

I believe it will be saves on the google search history

[Vectorash]

In a time interval (depending on Google and that site) Google comes and copies the site. Soon after people change something on the site Google comes again and copies the new version.

What you see in Google search results are the last copy of the site. The Cached versions are the previous ones Google copied.