Google Chrome:
https://support.google.com/chrome/answer/95582
Windows Internet Explorer:
http://windows.microsoft.com/en-us/windows7/how-to-delete-your-browsing-history-in-internet-explorer-9
Mozilla Firefox:
https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
Apple Safari:
http://support.apple.com/kb/PH17186?viewlocale=en_US&locale=en_US
What is a browser cache, you ask?
A cache is a repository for stored data that is used to expedite the process of retrieving data. There are several types of caches, including webpage caches, hardware caches, software caches and memory caches.
Caches are used to speed up a process so that data does not have to be recomputed or fetched from its original location and, therefore, saves time.