In most cases, the car brakes tend to make the grinding noise due to contact of the rotor disc with part of the caliper. This usually happens when the brake pads or rotors are extremely worn out. Another reason for the grinding noise can be a foreign object (stones, rocks, etc.) getting stuck somewhere in the calipers.
Brakes can also squeal when rotors rust or there’s high metal content in the brake pads (which is usually a concern in cheaper quality brake pads).
We recommend getting a brake inspection as soon as you notice squeaking or grinding noises.