On the computer keyboard, apart from the space bar and shift keys which are both used considerably, the next biggest key is the Caps Lock key which is almost never used, except by those who like to use all capitals all the time. These are probably the same people who immediately get onto the fast lane on the highway and stay there, irrespective of the level of traffic.
I myself hate the Caps Lock key. I almost never use it deliberately (how often does one need to capitalize every letter?) but I often find myself using it inadvertently. This because I do not touch type. instead using my own system that has worked well enough for me. The catch is that when typing, I am usually looking at the keyboard and not the screen. On occasion, I accidentally hit the Caps Lock key when intending to type the letter ‘a’ and when I later look at the screen, find a whole row or two of capitalized letters. I then have to change them to lower case using one of the menu options. It is not too much of a problem but is an irritation. There is also a menu option to reverse the process and change lower case to upper case that makes the Caps Lock key superfluous.
Daniel Colin James makes the case that this key has outlived its usefulness and should go and not continue to take up valuable space on the keyboard. He explains its origins.
The QWERTY keyboard debuted in 1873 on a typewriter that could only produce capital letters. A few years later came the Shift key, which toggled the typewriter’s output between lowercase and uppercase letters.
The Shift key physically shifted the internals of the typewriter, so it took some effort to press it down. Eventually, a Shift Lock key was created to hold it down. With Shift Lock engaged, letter keys produced their uppercase counterparts, but number keys produced symbols. That was a problem.
Doug Kerr was a telephone engineer working at Bell Labs in the 1960s. He watched his boss’s secretary repeatedly get frustrated after accidentally typing things like “$%^&” instead of “4567” in addresses because of Shift Lock.
So he did something about it. Doug Kerr invented the “CAP” key. CAP performed the same function as Shift Lock, except it only affected the letter keys.
“CAP” became Caps Lock, which made its way onto the computer keyboard, where it has remained part of the standard layout ever since.
James says that the key nowadays is usually used accidentally (like I do). He says that that space could be used for far more useful things and gives suggestions, such as ‘search’ or ’emojis’ that some computer makers are experimenting with.