A slip lead is a simple lead that loops around the dog's neck, combining both a collar and lead in one. It offers quick control and is often used for training or when handling dogs that need to be leashed quickly. However, it's important to note that slip leads, if not used correctly, can exert excessive pressure on the dog's neck, potentially causing discomfort or injury. Therefore, they should be used with care and for short-term use or training purposes only.