Shock collars, also known as electronic collars or e-collars, are devices used in dog training that deliver a mild electric shock to the pet when triggered by a remote control or automatically. They are often used to discourage unwanted behaviors, such as excessive barking or running away, by providing a negative reinforcement. These collars typically have adjustable settings to control the intensity of the shock, allowing trainers to find a level that is effective yet safe for the dog. While some trainers advocate for their use, others raise concerns about the potential for causing fear or anxiety in pets.