Originally Posted by
rp2pilot
To echo what Grumble said, VFR is merely a description of meteorological conditions, "VFR on top" is an actual clearance received from ATC.
If you want to be pedantic, VFR is set of regulations under which a flight can be conducted. Specifically, 14 CFR 91.151 through 91.165. (IFR is 14 CFR 91.167 through 91.199)
VMC is a description of meteorological conditions; Visual Meteorological Conditions.
It might not seem like an important distinction but it can be helpful in guiding you to the appropriate resource when researching a question.