Once you keep pencil marks, some cells end up with a single candidate written in them. That digit is the answer — there is no other digit it could be, by definition of what a candidate is.
The name matters less than the habit: after every entry you make, check the cells that shared a row, column or box with it. Removing one candidate from twenty neighbours is what creates obvious singles, and they usually appear in twos and threes.
A grid that keeps producing obvious singles is a grid you are solving correctly. When they dry up, that is the signal to move to hidden singles and pairs.