Supervision consists of watching over the conduct, demeanor and behavior of the players and also the physical environment as well. There are different types of Supervision: General, Specific and Transitional.
General supervision covers the broad area. For instance, the Coach or the Assistant Coach would supervise and watch over their players looking for players who are disobeying the rules, who might be playing too rough or aggressive or looking for someone whose "head is not in the game". In this case the Coach might either watch the player closely or he/she might take the player to the side and talk with them or have them take a break. Also in general supervision you have to watch the physical environment as well such as looking for potential hazards on or around the court, looking for glass, wet spots, dirt and making sure proper padding on the walls are secure, etc.
Specific supervision is when specific instruction is needed when a player is low skilled or when the player's behavior requires so. It involves direct contact with the players by the Coach, although not necessarily physical contact but visual and voice instruction as well. Some examples of visual and voice instruction is showing and telling a player how to do a proper lay-up, proper shooting form or the proper way to pass the basketball. Some examples of physical instruction is showing and demonstrating how to box out, proper Pick and Roll and hand checking.
Transitional supervision is used between general and specific supervision. This type of supervision is used when moving from a warm-up drill to teaching a new skill or when moving from one gymnasium or facility to another. For instance transitional supervision is used when moving from doing "suicides" (a running drill) to doing a 3-man weave lay-up drill.