What is Gyroscope ? & it's working principle

Definition:

Gyroscope is a device which use for measuring and maintaining orientation and velocity.

Usually gyroscopes take the form of a disc shaped object but can be any object that produces an effective gyroscopic behavior. Most of the gyroscopes mass should be as far away from the center as possible. This often results in a disc with a large heavy rim. When the gyroscope isn’t rotating it behaves like any other object, however when the gyroscope is spun on its axis at high speed it resists movements in certain directions.

Working Principle:

Gyroscope is working on the principle of conservation of angular momentum, which says that, total angular momentum of a system is contain both magnitude and direction if the resultant external torque acting upon the system is zero.