Time and again internet proved itself a beneficial tool in learning. Although now, typewriters have vanished, still there is a vast need to learn typing. If you know the skill, it makes work faster on your computer.
The cause of the letters on the keyboard are not sequential.
If you look at the keyboard of your computer and older typewriters, you will find that «Q, W, E, R, T and Y» are the first six letters and all other are mixed with each other. Who, however, decided this setting and why mix the letters?