What Are the Five Categories of Keys on a Keyboard?

Pretty much all computer keyboards include some of the same keyboard keys, including letters, numbers and special symbols. Some also have special function and command types of keyboard keys that can be used to give commands to a computer rather than simply for typing.

Every keyboard contains a set of keys known as the alphanumeric keys. The term "alphanumeric" refers to either letters or numbers, but not symbols or command keys. The number keys on a computer keyboard are often located in two different spots on the keyboard: above the letters and to the right of the letters. The number keys located directly above the letters double as symbol keys. Pressing shift and holding down a number will type whatever symbol is also on that number key. Symbol keys include the "dollar sign," the "percentage sign" and the "number sign." The letter keys are set up the same way from keyboard to keyboard. On the top row, the letters "Q,W,E,R,T and Y" are lined up. For this reason, this common layout is often called QWERTY.

The punctuation keys are the keys on the keyboard that relate to punctuation. Examples of these keys include the "comma key," the "question mark key," the "colon key" and the "period key." All of these keys – which can be located to the right of the letter keys – have multiple functions. For example, the "question mark key" doubles as the slash (/) key. The "colon key" doubles as the "semi-colon" key. Like the number keys, pressing shift while holding down a punctuation key will allow you to type the other function.

The navigation keys are located between the letter keys and the numbers keys on the far right of the keyboard. The navigation keys consist of four arrows: one pointing up, one pointing down, one pointing right and one pointing left. These keys move the cursor around your display screen, much like a mouse would except not as fluid. These keys come in handy when you are writing a document and want to move the cursor up, down, left or right on the page. Wherever the cursor lands is where the next letter, number or symbol will be typed. You can also use the navigation keys to scroll through the history of sites you have visited online.

Many computer keyboards have "function keys," beginning with the letter F. They're typically located at the top of a keyboard. These are used to invoke functions in various programs. For example, F1 is used in many Windows programs to open the "help" menu.

Command keys on a keyboard are keys that relay a command, such as "delete," "return" and "enter." Depending on your keyboard, you may have special keys up top – located above the numbers – that control the volume of your speakers, or the fast forward/rewind option when viewing a film. An eject key you press to load CDs or DVDs. The "control key" and the "alt key" can also be used in conjunction with other keys for shortcuts.

Many keyboards designed for Microsoft Windows have a "Windows key," with a Microsoft Windows logo. It can be used to open the Windows Start Menu. When it's used on other operating systems, it's sometimes called the "Super" key.

Common keyboard shortcuts include pressing "control" and "C" at the same time to copy a selected item, "control" and "home" to jump to the beginning of a document, and "control" and "end" to jump to the end of a document. Other special keys include the "caps lock key," the "shift key" and the "tab key."