What is an Internet history?
An Internet browsing history is a record that your web browser keeps of individual web pages that you have visited. Usually, it will be organized in reverse chronological order; that is, it will start with the last web page that you visited, and list the pages that you visited before that in order. It may also sometimes separately keep track of web pages that you've visited in individual browser windows or tabs.
Nearly every type of web browsers will have some sort of History option in one of its menus that you can use to view your browsing history, like so:
What is a cache?
A cache (sometimes specified as a "web cache") is a more specialized form of Internet browsing history. Instead of keeping track of entire web pages, it keeps track of specific elements on web pages, such as pictures, style elements, or any interactive content.
Think about it in terms of remembering what you ate today. Your Internet browsing history would be like remembering that you had toast for breakfast, soup for lunch, and steak for dinner. Your cache would be like remembering whether the toast had butter or jam on it, whether the soup was tomato or chicken noodle, and whether the steak was medium rare or well done.
What do caches and Internet browsing histories do?
Both caches and browsing histories help with memory, though in slightly different ways.
What Internet history does
Your Internet browsing history helps with your memory. Say that you're aimlessly browsing the Internet one day, and you come across this really cool or useful website. You spend so much time playing around on it that by the time you close your web browser, you can't remember where that website actually was. Thankfully, your web browser kept track of each page that you visited, so you can find that website again even if you visit a bunch of other websites in the meantime.
What a cache does
A cache helps with your web browser's memory. Your web browser can use its cache as a shortcut in order to speed up how fast it is able to load web pages for you. Besides shortening the amount of time you have to sit at your computer impatiently tapping your fingers, this also cuts down on the amount of data that your computer needs to exchange over the Internet. This may help you out with your monthly Internet bill.
Basically, it works like this: when your web browser loads a web page, it checks to see if it has parts of that web page already stored in its cache. If it does, then it just goes ahead and loads those parts without bothering to ask for them from the Internet server that the web page is actually on. Then it just asks for any new elements from the web server like it would normally, and adds those to its cache as well.
So, why are they important (in terms of privacy)?
Both your cache and your Internet browsing history can be used to track where you've been on the Internet. Mostly, this is used by certain websites in order to show you advertisements tailored towards what you supposedly like. Though relatively harmless, this is still a little creepy and privacy-invasive.
However, in rare cases, hackers may be able to use your cache or Internet browsing history to see where you go on the Internet frequently. This may mean that they can stalk you or more easily find and break into your accounts.
Either way, you're probably going to want to clear both of these things out every once in a while. We'll go over some more specifics in our next tutorial.