The cache exists because of a basic assumption made by browser designers: the internet is slow. It’s faster to get something from your hard disk than it is to get it from the internet. Even with today’s internet speeds, that still holds true. Browser designers noticed that most websites have many of the same elements on multiple pages. So the thinking is, why download the same logo over and over for every page especially frequently visited pages? Why not just download it once and then keep a copy so we can display it again without downloading it every time? That’s the browser cache. It’s nothing more than a place on your hard disk where the browser keeps things it downloaded once in case they’re needed again.

But over time after visiting hundreds of webpages the cache stores increase and can fill up the space needed to download more files. This is often the reason webpages load slower than before. For this reason it's a good idea to 'clear your cache from time to time'. See instructions below.