What is the primary difference between VFR and IFR flight rules?

The primary difference between VFR (Visual Flight Rules) and IFR (Instrument Flight Rules) lies in their reliance on navigation techniques and the conditions under which they are used. VFR specifically requires pilots to navigate and control the aircraft primarily by visual references to the ground and scenery. This means that pilots flying under VFR are expected to see and avoid other aircraft and obstacles based on what they can observe visually.

Conversely, IFR is designed for conditions where visual references may be limited, such as in poor weather or nighttime flying. Under IFR, pilots navigate by using flight instruments and are required to operate under air traffic control instructions. This establishes a structured environment where pilots can rely on their instruments to control the aircraft and navigate through conditions that might otherwise inhibit visual navigation.

Thus, the distinction fundamentally rests on the method of navigation, with VFR being visually based and IFR being instrument-based.