A dog collar is a piece of equipment worn around a dog's neck, primarily used for identification and control. Collars can hold essential information, such as a dog's name and owner's contact details, often displayed on a tag. They come in various materials, including nylon, leather, and fabric, and are available in different styles and sizes to fit various breeds. In addition to identification, collars can be used to attach a leash for walking and training purposes. Some collars are designed for specific functions, such as training collars that help with obedience or GPS collars that assist in tracking a dog's location.