What is cache???

can any one explain what cache is and what it means, and why its important? thatnks

Think of it like using telephone numbers. All the numbers you need are in the phone book, but it takes a long time to find them in there. To make things faster, you enter the numbers into your own phone so that you can dial them by simply selecting them.

Every time you need to call someone you haven't called before, you have to look up the number in the phone book. It takes a long time, so you add the number to your phone so that the next time you need to call them it will be faster.

In this analogy, the phone book is RAM Memory, and the list in your phone is cache. The CPU does the same thing that you do with your phone numbers - when it reads something from RAM it stashes a copy in the cache so that the next time it doesn't have to spend all that time waiting for it to come back from RAM.