What is Cache?

In my own terms, cache is a temporary place to keep a copy of information for faster retrieval on the second request for said information.  You might guess that I would continue on to say that information in this context is nearly anything you want it to be.  It could be a stretch to say that moving the coffee brewer closer to you is no different than saving a web page onto your local computer so that the next time you need another cup, or need to visit that web page again, it’s cached for quicker delivery.

And that’s exactly it.  Cache is nothing more than a mechanism that allows you to surf faster because the resources the page needs (images, the html page) are already available on the computer you are working on.  The page doesn’t need to reach out across the Internet to get that picture or other things.

Here’s another way to think of it.  Imagine you visit a particular site every day.  This site has a banner graphic across the top that is quite large, and every time you visit, it takes a while for the large header image to travel across the wires every time.  That sucks.  Really, it does.

If that header graphic was stored on your computer, the browser you are using could be set up to detect that you’ve visited this page before, and that large graphic is sitting right over here next to us.  Why bother to download it again when we have it right here!

Your browser can also be set up to detect when the graphic files are different and download the image to refresh your cache.

Most browsers are pre-configured to store some information into cache for quicker access to repeat data.

Remember Cache is different from Cache Memory