What is CACHE?
A temporary storage area for frequently-accessed or recently-accessed data.
When you download a web page, the data is cached, meaning it is stored temporarily on your computer. The next time you want that page, instead of requesting the file from the web server, your web browser just accesses it from the cache. That way, the page loads quickly. But if the web page is updated frequently, as may be the case with news, sports scores or financial data, you won't get the most current information. By using the Reload button on your browser, this timely data is updated by downloading fresh data from the server.
This is all very nice and useful, but what happens when you make some changes to your website. For example. you change some images or layout?
Your browser will happily oblige by using old information stored during your previous visit to the page and not the new changes you just made.
Your browser creates a temporary file of internet pages that stores a fixed amount of data ready for re-displaying the next time those pages or files are called for again.
This can be a real problem when several changes are made over a short period of time as you nsimply dont see the updates.
The browser reload button is supposed to force the webpage to be loaded from the server instaed of the cache directory, but in practice I have not found this very reliabe using MSIE.
The best option is to either set your browser defaults to force it to always look for a newer version of a page every time you visit it, or delete all your temporary files before viewing any new changes to a web page or file.
Note: ISPs also cache webpages to decrease display time by not requireing the server to send them to your browser. This is not likely to be a problem over a short period of time of script adjustments.
See also FAQ about templates_c directory