When you visit a website, data from that site is stored on your computer. This is called "cache" and it helps the website to load faster the next time you visit it by loading data from your computer instead of from the site's server.
Normally this isn't an issues, but occasionally you may want to force the website to send you new data. This is usually the case when a website is actively being worked on by a web-developer and you want to see the latest changes to the website.
For instructions and illustrations on how to clear the browser cache for your device please click here.