Crate training uses a dog's natural instincts as a den animal. A wild dog's den is his home, a place to sleep, hide from danger, and raise a family. The crate becomes your dog's den, an ideal spot to snooze or take refuge during a thunderstorm.
The primary use for a crate is housetraining. Dogs don't like to soil their dens.
The crate can limit access to the rest of the house while he learns other rules, like not to chew on furniture or electrical cords.
Crates are a safe way to transport your dog in the car.