Tilt and turn windows work by the simple turning of a single handle. There are three different positions for the handle, each of which allows unique functionality.
When the handle is pointed downwards, the window is securely shut.
When the handle is turned by 90 degrees into the horizontal position, the window functions a lot like a normal door. In this position, the locking pins are unlocked and the window vent turns open, held by hinges on one side of the window. There is one hinge on the upper corner and one on the lower corner, just like you would see it on a regular door.
Turn the handle 180 degrees, pointing upwards, the window starts operating differently. The hinge in the upper corner is disconnected. At the same time, a hinge in the other bottom corner of the vent is connected to the vent. The window suddenly tilts inwards, held by the hinges in the bottom corners.