It's called touch typing. On a manual typewriter of the Imperial and Royal Ilk when you are a young teenager (13 and 14) you don't quite have the stretch needed to reach those top keys whilst your concentrating on keeping the essential fingers on the home keys:
asdf, jkl;
For those who want to learn there is Type Faster and TypeFaster-Accessible:
https://sourceforge.net/projects/typefaster/files/
These are Windows executables and run under WINE. For UK users to use the accessible version you also need to install the basic TypeFaster app too as the accessible version does not contain the UK keyboard layout. The accessible one is good for someone with low vision - you have the option of having either the keyboard enlarged or the output enlarged or a compromise between the two.
I know there are native linux apps but they aren't as good, particularly for low vision users.