Produce a series of short straight line moves to depth (which breaks the chips into smaller pieces).
Increment
The distance the tool will feed down on each peck for Peck plunge moves. See Constant / Cutter Radius / Step Size.
Retract
In Peck plunge moves Retract is the vertical distance to pull out after one peck in order to pull out the chip. See Constant / Cutter Radius / Step Size.