caches etc...? Over a year ago I gave my computer to my sister, and I thought I had completely cleared everything on it. The internet browser reset (It is a macbook), which clears history, cookies, caches, private data, etc... So a couple of weeks ago, my sister's friend who apparently is very computer savvy was supposedly able to bring up all the websites I had looked at from long ago, as if the addresses or information had been stored somewhere else... Is that possible? If it is possible, how do you do it, and is there a difference between macs and pc's? What is it called?