Every web browser stores a cache of pages you visit (e.g. HTML pages, images, scripts that run on these pages) to reduce bandwidth usage and server load. This is called the browser's cache.
This is done to help speed up your access to commonly viewed pages so that images and scripts are available without the need to download each time.
For most browsers, clicking "Ctrl + F5" will be enough to hard-refresh your system, allowing you to see the latest features available following an upgrade.
However, that doesn't work for all iterations of all browsers, so you might want to double check the below site for further guidance: