Front brake normally disc type operate by hydraulic oil. Front brake absorb most of the car momentum, because braking throws the car weight forward on to the front wheels. This is the reason why most of the car front break is disc type, because it can perform more efficient by slowing down the car compare to drum type.
In the disc brake system, generally wear and tear part would goes to the pistons, disc, and brake pads. Therefore, your brake not functioning well, this item must be checked.
Consider to replace brake pad, service piston, and resurface disc/change new.