Well, it's hard to explain but on sites like deviantart, on your own profile when you click one of the tabs just one part of the page moves (so the whole page doesn't actually change) and a different tab lights up. I dunno if you know what I mean, but how is this done? Thankies.
What do you mean with moves? Do you mean that one part of the page moves but the rest stays as it was before then it's iframes, just search it up on google if you don't know what it is.
It will probably be Javascript. This executed client side, so the page doesn't have to be reloaded, and can control what is displayed.
That would be a JavaScript then. There's a much better example here: http://www.barelyfitz.com/projects/tabber/