Which brake system is this

So am I right to say that on the front I have a threaded stud and on the back a road brake?

No
As Andrew says, you have v-brakes on the front and the rear.

Here's a picture from the front

V-brake pads come with a threaded stud and washers to allow you to adjust the angle of the pad and the distance from the arm to the pad.

The "ball and socket" design allows the angle of the pad to be adjusted.
The different thickness of the silver washers allows for two different possible distances between the brake arm and the pad.