There are different kinds of dog collars and choosing the right one for your dog depends on his level of training and individuality.
When training young puppies, the best is the flat buckle collar made either of leather or nylon because it is the most simple and it will get your puppy used to wearing something around his neck.
For training older puppies and adult dogs, a chain collar is most often used. Chain collars apply pressure around the dog's neck to restrict unwanted behavior. These collars can be dangerous and injure your dog' neck and trachea so never leave your dog unattended while using the chain collar.
A milder version of the chain collar is the half-check collar which are usually leather or nylon with a small section of chain attaching to the leash.
Another alternative is the Martingale collar that consists of a double loop (a larger neck loop and a control loop which tightens when the dog pulls.
Slip collars are a combination of dog collar and leash, used mostly by show exhibitors. Slip collare are designed for dogs that are well trained.
A dog training shock collar is another way to control unwanted behavior.