Often when updates are made to a website, the changes are not immediately reflected on all computers around the world. Why is this?
It is mostly due to "caching". By default, most web browsers, including Chrome, Firefox, Safari and Explorer will save copies of key website files in their memory in order to display them quickly for you when you return to the website.
Each workstation or device will have different settings related to caching files, and within a certain period of time the browser will discard the old files and call up new ones. However to be sure you are seeing the most recent version of website, you can clear your browser cache manually.
See this guide to learn how: http://www.refreshyourcache.com/en/home/