Why do I need to clear or refresh my cache?
Your browser has a folder in which certain items that have been downloaded are stored for future use. Graphic images (such as buttons and icons), photo’s, and even entire web pages are examples of items which are saved or cached. When visiting a webpage your browser checks if a copy of the files on the page is in its cache already. If so, it will save the visitor some downloading and make webpages load faster.
There are some situations when bypassing your browser’s cache is preferred. Just clicking the refresh button (or hitting F5) won’t be sufficient in this case, because this reloads the webpage while still using the old files from the cache. You need to refresh your cache first!