Brake means to make a vehicle go more slowly or stop. As a noun, it refers to the piece of equipment that makes a vehicle go more slowly or stop. Break means to separate into pieces, to damage, to smash something. As a noun, it refers to a period of time when you stop working in order to rest.
brake (braked, braked) He braked sharply to avoid the cat. The driver braked but couldn’t stop the bus in time. The rear brakes are not working correctly.
break (broke, broken) He forgot his keys so he had to break a window to get into his house. Stop playing with my camera, you’ll break it! Let’s take a break and go for lunch.