What is the key difference between VFR and IFR?

The key difference between VFR and IFR lies in VFR, or Visual Flight Rules, requiring pilots to have visual references to navigate and control the aircraft. Pilots flying under VFR must be able to see the ground, overall scenery, and other aircraft to safely operate. This type of flying is generally conducted in good weather conditions where visibility is sufficient, allowing pilots to maintain situational awareness.

In contrast, IFR, or Instrument Flight Rules, does not depend on visual references. Instead, pilots flying under IFR utilize instruments in the cockpit to navigate and control the aircraft. This is essential in conditions where visibility is poor, such as during clouds, rain, or fog, allowing for safe operation regardless of outside weather conditions. This distinction highlights the fundamental operational strategies employed under each set of rules.

Other choices do not capture the primary function of VFR and IFR. For instance, altitudes and applicability to specific flight types or times of day are not defining characteristics of VFR or IFR and do not reflect their operational differences.