The brake system in a car is normally controlled by foot pedals, unless it has been customized to have hand brakes. Reasons for customizing to hand brakes could be for a person that is unable to use their legs while driving. There is not a difference in the braking power when controlling the brakes by hand or foot. Both are equally as effective in controlling the braking of a car.
The emergency break on a car can be located on the floor board, in which case you would control it with your foot. It may also be located to the right of you, which you would control with your hand. In this case, people prefer the hand brake to the foot brake. It is easier to access in the case of an emergency, and you are able to make sure you have it fully engaged when parking on a hill.
This is something to consider when purchasing a car. You will want to know if the emergency brake is operated by the foot or by the hand. Whichever brake you feel you can activate the quickest and the most thoroughly, is the one you want in the car you are purchasing.