Clearing your Cache is only part of clearing your browsing history.
You will notice that in the instructions for most browsers you are told to Select Delete Browsing History AND also to select Temporary Internet files, Cookies, and History.
The following is more info about cache, cookies, and history.
Each time you access a file through your web browser, the browser caches (i.e., stores) it. By doing this, the browser doesn't have to newly retrieve files (including any images) from the remote web site each time you click Back or Forward. You should periodically clear the cache to allow your browser to function more efficiently.
Also see this FAQ:
Refresh Your Browser / Clear Cache and Cookies / Reboot
A cookie is a file created by a web browser, at the request of a website, that is then stored on a computer. These files typically store user-specific information such as selections in a form for hassle-free automatic logins, shopping cart contents and shopping cart functionalities, data authentication, third party ad serving, ad management, preference setting, language setting, among many others.
Browsers will normally clear cookies that reach a certain age, but clearing them manually may solve problems with web sites or your browser.
Why even bother to delete cookies?
Cookies are just small .txt (text) files that by themselves cannot hurt your computer. Cookies are 'set' by almost every web-site that you visit, on every visit. You can delete all your cookies today, and by tomorrow you will have dozens again just be visiting web-sites.
Cookies do not slow down a computer, at least the first million or so that you might have on your computer.
They are not a virus or spyware, BUT some people consider 'tracking' cookies to be an invasion of privacy.
Tracking cookies are usually '3rd party cookies' from advertising servers. They can track your movements around the web in order to deliver to you customized, targeted advertising.
It all depends on one's personal attitude, whether you consider tracking cookies some kind of threat. Some anti-spyware programs do not even report tracking cookies as even a minor threat.
As cookie technology evolves along with website publishing and advertisement technology, privacy issues are sure to arise time and again.
While cookies by themselves cannot dig or research your information on your computer, they do store personal information in at least two ways: They form information and ad tracking. This personal information is not generated by the cookies themselves, but by your own input into websites' order forms, registration pages, payment pages, and other online forms.
Often used for e-commerce, this information is often encoded and protected from hacking by the remote server through limited interaction via security features like secure sockets layers (SSL) certified pages and similar network security schemes.
A browser's history is a log of sites that you visit. When you press a browser's Back button, you are moving back one entry in the history log. Browsers will normally clear their history at regular intervals, but you may want to clear it manually for privacy reasons.
Click Here to access instructions for clearing cache using different browsers.
From this article:
Important: How to refresh your browser's cache