RAM (Random Access Memory) is at the centre of your computers performance. You could have the fastest drive in the world and the most powerful processor money can buy, but if you don’t have enough RAM, you’re in trouble.
I like to think of RAM as a Desk. Your Hard Drive is a Filing Cabinet. The bigger your desk, the more files you can have open at a single time. You can quickly and easily reach any file that is open on your desk. What happens when your desk gets too full? You have to file stuff away in the filing cabinet. Just in the same way your computer puts things on the Hard Drive when your RAM gets too full. This process in a computer is called Paging.
So now you have stuff in your filing cabinet (Hard Drive) and on your desk (RAM). You need to work on that file that just went into the filing cabinet. Oh dear, you have to go find it now. Takes ages doesn’t it?
Wouldn’t it be quicker if you could open everything on your desk?