newbie : what is the diff between macro and standard zoom ?

Hi

I was studying macro photography. What the books say is that macro lenses are used for closeups. What they dont tell me is how this is different from using a zoom lens to zoom onto a subject.

So whats the difference ? I was more furthermore confused by the fact that there is category of telephoto zoom lenses that have "macro capability". What does this really mean ?

thanks for your answers...