This is a very basic question, but what is orbital angular momentum actually? I know it can be quantized as zero, 1, etc. What is it in layman's terms? I tend to understand it in terms like the earth orbiting the sun. Spin on the other hand is either right or left spin. So what do the different numbers of orbital angular momentum mean? If it were the earth rotating around the sun, would it be like different ones orbiting at different angles to the axis of the sun?