What is degrees per second?

The degrees per second is a measurement used for defining angular velocity. This is not the standard unit for measuring angular velocity. It is rad/s which is a SI unit. Unit of degrees per second is $\deg/s$ or $\deg*s^{-1}$.

$$1\ \frac{deg}{s} = \frac{2\pi*\omega}{360} = \frac{2\pi*rad*s^{-1}}{360}$$

What is radians per second?

The radians per second is a measurement used for defining angular velocity or rotational speed. This is the standard SI unit for measuring angular velocity. Unit of radians per second is $rad/s$ or $rad*s^{-1}$.

$$1\ rad*s^{-1} = 1\omega = \frac{360}{2\pi} deg*s^{-1} = \frac{1}{2\pi} Hz = 0.159155 Hz$$

Wikipedia page for explanation on Radian per second