Let's let the radius be 1 earth radius. We call it the angular frequency, however it's related to the angular velocity. It tells us the rate at which the Earth travels around the Sun, i.e. how many time per year. The units of omega are radians per second. This is what a sinusoidal looks like.
Time is in units of days.
A perid of a sinusoidal function is defined as when the curve returns to the same value. This is called the frequency and the symbol used for frequency is f. Now change then angular frequency to 3. We can use the same expression for y to describe the motion of a mass as it bobs up and down on a spring. Y will represent the displacement of the mass about its equilibrium point.