To determine what VFR is, you have to know the existing conditions, whether it's day or night, your altitude, the airspace you'll encounter, and the airspace you are in. Airspace is designated Class A, B, C, D, E, or G (there is no F in the United States)....
“see and avoid.” The presumption made in establishing the basic VFR weather minimums is that aircraft flying at lower altitudes (i.e.,below 10,000 MSL) and/or in airspace with radar approach control and/or an operating control tower (i.e., Class B, C, and D airspace) will be ....