What Are the Five Categories of Keys on a Keyboard?

By Noel Shankel

A computer keyboard contains numerous letters, numbers, symbols and commands in button shape, each of which belong to a specific category of keys. Knowing what each category of key means will help you figure out the function of the key. Some keyboards may have special keys that others do not, but all keyboards share the same alphanumerical keys.

Alphanumeric Keys

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 are 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, keypads on cellphones are known as QWERTY keypads.

Punctuation Keys

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.

Navigation Keys

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 Websites you have visited.

Command Keys And Special Keys

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 function keys -- also located along the top of the keyboard -- can be used in conjunction with other keys for shortcuts. The "control key" and the "alt key" can also be used in conjunction with other keys for shortcuts. 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."