Images, files and pages on websites are stored (cached) in your web browser. This saves time and system resources so they don't have to be retrieved each time from the server.
Cache is only updated every 24-72 hours, so your browser could be displaying outdated information. By clearing the browser cache, you are telling it to forget what is stored and go redownload the items again. Sometimes clearing the cache still doesn't resolve the issue. If this happens, you will need to call your ISP and ask them to manually flush their current cache.
To see new changes to the website, you need to clear your browser cache and refresh your page (hit ctrl F5 at same time).
Select the browser you have to view instructions for clearing the cache.