The Instrument Rating allows you to fly in cloud navigating solely by reference to the flight and navigation instruments. Building on the skills from your previous training you will learn to control the aircraft precisely "on the instruments" to fit in the air traffic system. As a result you will be able to fly safely when visual navigation is marginal or not possible.
Considered mandatory by most Commercial Operations, the Instrument Rating will also benefit the Private Pilot by allowing more capability and flexibility as to when to fly, and the background knowledge of man, environment and machine, to know when not to fly.
Building on your visual flight experience, the Instrument Rating definitely will take your flying to the next level.