Service connection consists of a ferrule, stopcock, and gooseneck.

Explanation:
1. Ferrule: A ferrule is a ring or cap placed around the end of a pipe to strengthen it or to hold together different pipes. In the context of a service connection, the ferrule is used to connect the main water supply pipe to the service pipe.

2. Stopcock: A stopcock is a valve that controls the flow of water in a pipe. It is typically used to shut off the water supply or to regulate the flow. In a service connection, the stopcock is installed near the ferrule to control the water supply to the service pipe.

3. Gooseneck: A gooseneck is a curved pipe or tube that allows the connection between the stopcock and the service pipe to be flexible. It provides a bend or curve in the pipe to accommodate different angles or positions. The gooseneck helps to prevent any stress or strain on the connection and allows for easier installation and maintenance.

The combination of the ferrule, stopcock, and gooseneck is commonly used in service connections for water supply systems. The ferrule provides a secure connection between the main water supply pipe and the service pipe. The stopcock allows for the control of the water flow, and the gooseneck provides flexibility in the connection.

By having these components in a service connection, it becomes easier to install, maintain, and control the water supply to individual properties or buildings. The ferrule ensures a reliable connection, the stopcock allows for control of the water flow, and the gooseneck provides flexibility in the installation process.

Overall, the combination of a ferrule, stopcock, and gooseneck is a common and effective way to create a service connection in water supply systems.