When website changes don't appear as expected

In order to speed up web browsing, web browsers are designed to download web pages and store them locally on your computer's hard drive in an area called "cache". Browser cache (also know as Internet cache) contains records of every item you have viewed or downloaded while Internet surfing. So when you visit the same page for a second time, the browser speeds up display time by loading the page locally from cache instead of downloading everything again. (from http://refreshyourcache.com/en/cache/)

Hitting the refresh button on your browser will cause the page from the internet, therefore showing any recent changes. Each browser (Chrome, Firefox, Explorer) has the button near the URL bar and it looks like a "recycle" icon.