A choke chain, also known as a training collar or slip collar, is a type of collar that tightens around a dog's neck when tension is applied to the leash. Although choke chains are commonly used in dog training, they can be harmful and cause injury if not used correctly. As a result, many trainers and dog lovers prefer gentler alternatives. Some synonyms for choke chain include martingale collar, pinch collar, prong collar, and slip leash. These training tools work by guiding a dog's head or offering more control without causing physical harm. It's important to research proper usage and decide what's best for your pup's temperament, size, and training needs.