When you visit a website your Web Browser stores a copy of what it downloads to speed up browsing. Sometimes your browser might not update itself when changes are made. Clearing the browser cache will ensure you are viewing the latest version of a page.
"Shift Clicking" on the refresh button will often force a page reload without using cache. Alternatively you can navigate through the menus.
Tools -> Internet Options -> Delete Files... -> Check "Delete all offline content" and click OK
Tools -> Internet Options -> Delete... -> Uncheck everything except for "Temporary Internet Files" and click Delete
Tools Menu -> Clear Private Data... -> Uncheck everything and click "Clear Private Data Now"
Safari -> Empty Cache -> Empty
Tools -> Delete Private Data -> Uncheck everything except for "Delete entire cache" and click Delete