I don't know if this is common knowledge but it seems like so many people who fill out online forms never realize that they can use the tab key to skip from one field to the next! This is so much faster and easier than reaching for the mouse, clicking the cursor, clicking the next field and then putting your hands back on the keyboard. It also eliminates the chance of accidentally pressing the enter key which could submit the form (depending on how the page is designed).
When you press the tab key it moves to whatever the web page designer has set up as the next element to be viewed. This can be a text box, a radio button, a checkbox, a button or anything else that can be clicked with a mouse. If you hold down the shift key while pressing tab it changes the direction that the tab moves so you can go back to an earlier element.
So for example if you're filling out a job application and you press tab after entering your surname you should end up on the "Hire Date" field at the 1-inch mark where you can start typing your date. This is what you should expect if the page is designed properly.
But sometimes the order isn't right. For example, the first More link in a sidebar navigation menu will get focus by default, but once you pass this element and hit the tab key again, it goes to the second More link which may or may not be what you want (depending on the way the page is structured). This is a problem that can be solved using an iframe, but I'll discuss this later in this article.