The purpose of a braking system is to slow and stop your vehicle. It is controlled by a foot (service brake) pedal and by a hand or parking brake.
The brakes also allow you to make an emergency stop if you need to.
It is therefore important that you ensure that your braking system is maintained and operating at optimum levels. It is a legal requirement that your braking system performs as intended and your brakes will be tested as part of your MoT.
Like all components, brakes and indeed braking performance deteriorate over time and because it happens gradually, many people don't notice the difference in their braking system. Having your brakes checked regularly could also save you time and money by preventing damage to other components.