Liner and Cut back

Can anyone explain to me in plain english what it mean when they name a machine for a cut back machine opposing to a liner? I am not a scratcher but my english skills arent the best specealy on the technical terms

A cutback is just that.The front spring on a cutback is shorter or "cutback" as opposed a standard length front spring.

OK But what does it do that a normal (no-cutback) liner doesn´t???

In the old days tattoists only had 1 gauge of steel to use for springs, so to make a machine run faster they "cut-back" the front spring. Nowadays it's doesn't matter whether a liner is cut-back or not, as you simply use a thicker gauge spring to achieve the same effect.

cutbacks run faster than a standard liner due to shortening of the front spring.