Look closely at your keyboard and concentrate on the F and J keys. In most of the cases you will probably notice a little raised line or bump below them. Almost all modern keyboard models come with this feature. You will notice that only the F and J keys are having this feature.
SO WHY IS THERE BUMPS ON THE F AND J KEYBOARD KEYS? HERE’S THE REASON.
These are to help us position our fingers correctly so that we are able to type without looking at the keyboard. If you balance your hand correctly using these bumps it improves your typing speed and makes it easier to use the keyboard.
The F and J keys were specially used for this purpose. These keys are referred to as the home row. The bumps on these keys enable you to position your hands on the keyboard without looking in a manner that is optimal for touch typing.