What is the difference between clear cache and flush cache?

The /clearcache page is used to clear site data, such as products, categories, and navigation menus.  For those using a custom skin, the /flushcache page clears skin data, like that controlled by the layout.txt file.  Simply add /clearcache or /flushcache to the end of the url for your site to see these pages. 

If your website domain/url were "websitename.com",
to instantly see recent changes made to products, categories, and navigation menus you would go to the websitename.com/clearcache page and click the button . If your website were  "example.com", you would use  example.com/clearcache instead.

In the same example
, to see recent changes made to the skin you would go to the websitename.com/flushcache page and click the button.