The brake calipers and brake pads of the car are producing friction with the brake rotors for stopping the car. If the brake caliper of the car is not functioning properly, then you will face problems for halting the car. But several problems in the brake system components may cause sticking issues in the brake caliper. If you want to pinpoint the sticking brake caliper of the car, then go through the following video.
https://www.youtube.com/watch?v=R4ZXelclRCQ