Difference Between Cookies and Cache

Cookies are relatively small amounts of data that a website saves to your computer while you are viewing a web page. Cookies usually contain information such as your user name or a saved password, so that the website can identify who you are when you return to the site later on. Usually any data in the cookie is encrypted or in a form only readable by that particular web page, so you don't have to worry about sensitive data being stored in your cookies (as long as the web site you visit is trusted). 

The cache is also a repository of saved data, but the cache stores any files needed to view a website (text, images, other media) so that the page load time is shorter if you happen to visit the page again in the future. For example, if I have a 1 MB image on my home page, it would be a hassle to load the image from the Internet again and again -- instead, the local copy of the image in the cache is loaded into the browser, making the overall load time a lot faster.