To make the "back" and "forward" buttons of your web browser work, web browsers store copies of pages to display quickly to better facilitate this kind of navigation. These pages are referred to as "offline" or "cached," but because the portal is being constantly updated with new information, local caching of data could result in incorrect information being displayed. Therefore, it is best to use the links and tabs available to you to navigate throughout the portal.
My Missouri State also has a variety of external links, or links that take you outside of the portal to other resources such as the Web Strategy and Development page or the Help Desk website. When you click on these links, a new browser window is opened and you can navigate between browser windows using the bar (usually) located at the bottom of your screen. Most modern web browsers will open a new tab rather than a new window, and these can usually be found near the top of your web browser.
Because external links open in new windows or tabs, you will be unable to click the "back" button to return to the portal. Rather, you will either need to click on the tab/window that still displays the portal, or close the tab/window that opened due to the external link.