Angular momentum is the angular version of momentum. The math is a little bit more complicated, that's all. Hopefully everyone knows that an object in motion tends to remain in motion at a constant velocity unless acted on by a force. That's because momentum is conserved. read more
Angular momentum is conserved, and the only way for an object to stop rotating is if its angular momentum is transferred to another object. (That's what torque is: the transfer of angular momentum.) Now, based on real life experience, we know that rotation is not really "conserved". read more
Most of us are familiar with good old fashioned classical angular momentum. The classical description of angular momentum is basically “what keeps you rotating”. It is the rotational analog of linear momentum. Classical angular momentum is always measured with respect to some point (formally, [math]\vec{L} = \vec{r} \times \vec{p}[/math]). read more
The spin orbital momentum is the component of momentum associated with the the rotation of the body about its center of mass. The total angular momentum is the vector sum of the spin angular momentum and the orbital angular momentum. Consider the earth relative to the sun. Ignore the earth's moon just for purposes of this illustration. read more