Which tool is designed to install and remove spark plugs?

The tool specifically designed to install and remove spark plugs is the spark plug socket. This tool features a deep well that accommodates the length of spark plugs, which typically have a considerable reach. Additionally, spark plug sockets usually include a rubber insert or a magnet that helps to grip the spark plug during installation and removal, preventing it from falling, which can happen with standard sockets.

While a ratchet or socket driver is necessary to apply the torque needed to turn the socket, they by themselves are not designed exclusively for spark plugs. A torque wrench, on the other hand, is used to apply a specific amount of torque to the spark plug once it is installed, ensuring it is tightened to the manufacturer's specifications, but it does not directly install or remove the spark plug. Therefore, the spark plug socket is the tool specifically tailored for that task, making it the correct choice.