What is the meaning of the Rabi Frequency in the context of an RF field applied to an NMR setup?

I believe it's named $$\omega_1$$ (correct me if I'm wrong) equal to $$\gamma B_1/2$$. The fact that it's equal to $$\gamma B_1/2$$ allows me to see how it works mathematically after a quick calculation, but what actually is the physical meaning of the Rabi Frequency $$\omega_1$$ for an RF field applied to an NMR setup? And how does it differ from the RF frequency $$\omega_{rf}$$?

The broader context I'm working with here is quantum control on an NMR system, unfortunately I don't know the actual physics of this very well, I've just been working with the theoretical stuff such as mapping the dynamics of these kinds of systems on to a Bloch sphere.

The frequency of the applied rf field $$\omega_{rf}$$ is normally equal to the Larmor frequency at which the spin precesses in the static magnetic field, and its direction is perpendicular to the static field. Consider a frame rotating about the static field at the Larmor frequency. The frequency $$\gamma B_1/2$$ is the rate at which the spin expectation value rotates about a direction perpendicular to the static field when the rf magnetic field with amplitude $$B_1$$ is applied.