On Apple menu-system preferences-keyboard there are two choices-key repeat and delay until repeat. What are they meaning? I mean, I have a keyboard, and there I want to make a lot of dots quickly just holding down the dot key. As in PC is possible. But I can't here. Do the two choices have an affect to the quick dot line.. ?

Unless you're having problems I'd just leave them at the default settings, but you could certainly try different settings and see what effect they have with your typing speed -- if they don't have any noticeable effect then you can just set them back to the default values. Btw, at the default settings of those options I get repeated dots by holding down a key.................