JohnMcGrew answered your question a couple of days ago. It is just the same as hitting "enter" on your keyboard. It initiates loading whatever the url is that is in the url box. That can be pasted from your browser, or from notes that you may have somewhere. I usually hit enter after pasting, but hitting the "Go" button is an alternative. If you hit it when you are at a page that was previously navigated to, it is the same as hitting the "reload" button.