My 06 model corsa 1.8 GSi has disks in front and drums in the back. Very common for "4-bolt wheel" cars.
Oclerouxenator, disks are clamped from either side by the brake pads. Drums fit over the pads so the pads push outwards against the inside of the drum to slow it down. Imagine the drum (attached to your wheel) being a big circle. The brake pads (aka shoes) are a small circle inside the big circle. When you hit the brakes, the small circle swells up and pushes against the inside of the big circle, causing friction.
http://static.howstuffworks.com/gif/drum-brake4.jpg
Oclerouxenator, disks are clamped from either side by the brake pads. Drums fit over the pads so the pads push outwards against the inside of the drum to slow it down. Imagine the drum (attached to your wheel) being a big circle. The brake pads (aka shoes) are a small circle inside the big circle. When you hit the brakes, the small circle swells up and pushes against the inside of the big circle, causing friction.
http://static.howstuffworks.com/gif/drum-brake4.jpg