The gyroscope is basically a massive rotor that is fixed in light supporting rings called gimbals. The gimbals have frictionless bearings that isolate the central rotor from outside torques. The spin axis is defined by the axle of the spinning wheel. The rotor spins about an axis, with three degrees of rotational freedom. Having thus acquired extraordinary stability of balance at high speeds, it maintains the high speed rotation axis of its central rotor.
When the gyroscope is applied with external torques or rotations about the given axis, one can measure the orientation using a precession phenomenon (precession refers to the change in the orientation of the rotational axis of a rotating body)