Three types of braking are commonly in use on trams.
Regenerative braking is used for general service stops. It gives smooth, controlled deceleration and can result in power savings.
Frictional axle braking is used as a parking brake and as part of the emergency braking system. The brake is applied by a powerful spring and compressed air is used to release it. If the air supply fails, the brake automatically comes on.
A magnetic track brake is used for emergency stops and is completely independent of the wheels or power supply.
It is now modern practice to automatically blend together the operation of the different braking systems so that the smoothest deceleration is obtained and the vehicle is brought to a jerk-free halt at every stop. This is one of the reasons why such a high proportion of standing passengers is permitted on a tram.