Keyboards are by far the default way most of us have been using to interface with our computers ever since computers came along. I guess, there’s just something about keys that we want to press them.

Keyboards also are often the most overlooked aspect of computer innovation. The standard 104 key keyboards that you see on your computers, laptops and even smartphones today has come a long way down from the complicated mammoth it once was.

As we focus more on getting the most clock speed or bottling up as much RAM, we overlook the subtle innovations the keyboard undergoes. And it is these subtle innovations that add up to the entire user experience of a computer.

Despite all of this, there are still aspects of the keyboard which might come off as redundant or even unnecessary. In this article, we take a look at the good old modifier keys — what are they and why you have two of them on your keyboards.

Also read: Keyboards and wrist rest: A writer’s guide to comfortable typing

What are the Modifier keys?

As you can guess, going by the name, they are used to modify a standard input character by some other key. However, it can be a tad bit more complicated than that.

These keys don’t have any function by themselves but become super useful for combinations. Keyboard shortcuts as we know them wouldn’t be possible today if not for modifiers.

The ‘Shift’ key, for example, alters the output of character keys. Any alphanumeric key you press while holding down the shift key will produce an alternate symbol or character. The ‘Control’ and the ‘Alt’ keys don’t alter outputs but provide for other functions such as keyboard shortcuts.

The number of modifier keys on a keyboard has also been long debated and experimented. Some older keyboards, most notably the ‘Space Cadet’ Keyboard found on MIT LISP machines had no less than seven modifier keys.

These keys included four control keys namely — Ctrl, Meta, Hyper and Super and three shift keys — Shift, Top and Front. All these keys allowed users to type up to  8000 possible characters. These were dropped later on though to make keyboards more comfortable to use by the general public and have combinations that didn’t need reference guide of their own.

Why do we have two modifier keys?

Now that keyboards were scaled-down and made easier to use by just adding three primary modifier keys, there’s another question, why two of each? Eliminating redundant keys would make for a lot cleaner keyboard layout.

The answer is more straightforward than you think. The second keys are there to make typing easier. Having on key on each side of the keyboard allows users to more comfortably access keyboard shortcuts and any other custom combinations they might build up. It also accommodates left or right-handedness.

Try typing in the question mark with the left shift using one hand, and you’ll suddenly have a lot more gratitude for the way the keyboard was designed.

Also read: Top 7 wireless mechanical keyboards