A cache is a fast storage area that keeps recently used data, such as images or page files, so a site loads faster next time; a cookie is a small piece of data a website saves on your device to remember things about you, such as being logged in. Clearing your cache speeds up loading; clearing your cookies logs you out and forgets your preferences.
The core difference
A cache stores files for speed; a cookie stores information about you and your visit.
- cache — a fast storage area holding recently used data for quick retrieval: clearing your browser's cache can fix a page that won't load properly.
- cookie — a small piece of data a website stores on your device to remember information between visits: the site uses cookies to keep you logged in.
How to tell them apart
A cache is about speed: it is a copy of files the browser already downloaded, so it does not have to fetch them again. A cookie is about memory: it is a small note the site leaves on your device so it recognises you next time, such as remembering your login or shopping basket.
The mix-up happens because browser settings often group "clear cache" and "clear cookies" together under one menu, so people assume they do the same thing. In fact, clearing your cache just forces the browser to redownload files, while clearing your cookies signs you out of sites and resets any saved preferences. Outside computing, cache also keeps its older meaning of a hidden store of supplies, as in a cache of buried equipment.
