Angular velocity is the
dimension of
angle/
time for the measurement of
rotation, but
rotational
velocity is the
dimension of
rotations/
time. It's confusing because
rotation is ambiguous: It can mean "1 turn" or it can mean "turning at all."
Angular velocity is usually measured in units of radians/second or degrees/second, but rotational velocity is most often seen as units of cycless/minute, or RPM, where "1 turn" = 1 cycle.
It's a subtle difference, but the difference is confusing, since one hardly ever sees cycles in an equation. The cycles are always just assumed.
1 cycle = 360 degrees
= 2 x pi radians
= 1 (full) rotation
Frequency, for example, is also measured in units of cycles/time, but again, you hardly ever see the cycles in equations for frequency.
It always just shows up as 1/time or 1/second.