The front black part is a ratcheting mechanism which can be turned into 3 different positions; forward, reverse or fixed driving. The bit can be pushed into the metal bar in the front (there’s no magnet, it’s a mechanical lock, so you have to push the bit in until it clicks).
 
The black button on the middle of the handle can be pushed so the screwdriver can change from regular, pistol grip, or t-handle design.

An there’s bit storage in the back.

Please see attachments for illustrations.