Feature integration theory is a theory of how people remember information. It says that when you process information, you break it down into individual features (like size, shape, color) and store each one in a special place in your brain. When you try to remember the whole thing, your brain has to put all these features back together again in the correct order. So for example, if you are trying to remember a certain apple, you have to remember the size, shape, color and anything else that made that apple special.