Torque is the rotational equivalent of force. Force causes linear acceleration; torque causes angular acceleration.

Angular momentum is the rotational equivalent of linear momentum. Both are conserved in closed systems.

Both describe motion; linear uses displacement, velocity, and acceleration, while rotational uses angular displacement, angular velocity, and angular acceleration.

Angular displacement: $\Delta\theta$ | Linear displacement: $\Delta x$. $\Delta\theta = s/r$, where s is arc length and r is the radius.

Angular velocity: $\omega$ | Linear velocity: v. $\omega = v/r$, where v is linear velocity.

Angular acceleration: $\alpha$ | Linear acceleration: a. $\alpha = a/r$, where a is linear acceleration.

Torque: Causes rotational acceleration. | Force: Causes linear acceleration.

Moment of Inertia: Resistance to rotational motion. | Mass: Resistance to linear motion.

It causes angular acceleration.

Their moment of inertia decreases, and their angular velocity increases to conserve angular momentum.

Total angular momentum remains constant.

Increasing the radius will increase the moment of inertia, making it harder to change the object's rotational motion.

Increasing the mass will increase the moment of inertia, making it harder to change the object's rotational motion.