Raking is a low-skill attack that can easily defeat low-quality locks. The rake is a metal strip (often wave-shaped, but others exist) which you have to move around inside the keyway while applying torque. Some of the pins will randomly get caught at the shear line; repeat until the lock is opened. This type of attack can be prevented by using security pins (like spools, barrels, or serrated pins) that get stuck in the shear line.
A comb attack is different. Some locks are so poorly designed that you can use a comb-shaped tool to lift all of the key pins above the shear line and completely bypass the security.
Raking is a low-skill attack that can easily defeat low-quality locks. The rake is a metal strip (often wave-shaped, but others exist) which you have to move around inside the keyway while applying torque. Some of the pins will randomly get caught at the shear line; repeat until the lock is opened. This type of attack can be prevented by using security pins (like spools, barrels, or serrated pins) that get stuck in the shear line.
A comb attack is different. Some locks are so poorly designed that you can use a comb-shaped tool to lift all of the key pins above the shear line and completely bypass the security.