Why "F" and "J" on the keyborad There is a bulge?

Consider more closely the button on your keyboard as well.

I'm sure most of you underestimate the "bulge" that existed at the letter "F" and "J".
Now that you noticed, some of you would ask, "What is this bulge?"

It turned out that this bulge is created with a simple goal: Make it easy for people who type a la touched-type to determine the position of their left index finger (the letter "F") and their right index finger (the letter "J").

And what was touched-type?

Touch-type is one way people type in which they are not looking at the keyboard while typing.
Some people are typing in this way. It is therefore a kind of assistance they need to know the position of their fingers while typing and the "bulge" was chosen as their assistance.