Layering the same takes has been used ever since the 60s, and reached it's peak in modern era with digital recording, where you are not bound by the limitations of having a limited number of tracks to record on.
The whole point of doing this type of recording is to get a wider, fatter sound out of our instrument by layering the recorded sounds. Double tracking means recording an instrument two times etc. Ok, for some of the readers who might not be familiar with this terminology, in music production slang, when we say single tracking, it means recording an instrument only once.
