Some people think having their dog in a crate is a cruel punishment, like being in jail. However, they are thinking like a person, and not like a dog. Once your Cavalier is used to his crate, he sees it as a safe place, where nothing can hurt him. It is his cave. He will especially like it if his crate has comfy bedding.
Crates are especially important for young dogs who are impulsive and curious. His crate keeps him safe from biting electrical cords, having things fall on him, and keeps your house safe from him. Your slippers are safe.
Crates are also important in housebreaking. Dogs instinctively don’t like to soil in their bed. When your dog is crated at night, for example, he may get through the night without soiling his crate… but get him out quickly in the morning, as his little bladder will be full.
If you travel, your Cavalier travels in his crate for safety in the vehicle. He doesn’t mind it because he is in the comfort of his crate. If you stay in a hotel, his crate goes with him, so he feels right at home.