If you look at any computer keyboard, the F and J keys will look different from the others.

 If you look at any computer keyboard, the F and J keys will look different from the others.

This is because the F and J keys have lines. But why does this happen and why don't the rest of the keys have lines?

The answer is quite interesting and may be familiar to you if you have ever taken a computer class.

The F and J keys are also known as homing bars and the lines on them serve a specific purpose. Basically, it is meant to help you type without looking at the keyboard while typing with both hands.

That is, place the first finger of the left hand on F and the index finger of the right hand on J and then start typing. These lines tell your brain that your hands are in the right position for typing because those lines are felt by the fingers.

These lines let the brain know where the F, D, H, or other keys are and where to move the fingers while typing.