“Brake” is a noun. It’s part of a vehicle or piece of machinery that stops or slows motion.
“Break” is a verb. It’s when you take something that should be in one piece and make it so there’s more than one piece.
The two words even have all the same letters as each other; the only difference is where you put the vowels. Remember it this way: if you break a glass, you almost always say “eek!” as it falls and shatters. “Eek” and “break” have the vowels together. Brake separates the vowels, the same way a brake separates you from travelling at speed.