VFR - Visual Flight Rules

A flight carried out in accordance with the visual flight rules. Except when a clearance is obtained from an ATC (air traffic control) unit, VFR flights may not take off or land at an aerodrome within a control zone, or enter the aerodrome traffic zone or traffic pattern, when the ceiling is less than 1500 ft (450 m) or when ground visibility is less than 3 miles (5 km). VFR flights also may not be operated above flight level 200 and at transonic and supersonic speeds unless they are authorized by the appropriate ATS (air traffic services) authority. VFR flights may not operate above FL 290 (flight level 290) in areas where a vertical separation minimum of 1000 ft (300 m) is applied. VFR flights may not be operated over congested areas or an open-air assembly of persons at a height less than 1000 ft (300 m) above the highest obstacle within a radius of 2000 ft (600 m) from the aircraft and elsewhere at a height less than 500 ft (150 m) above the ground or the water.

IFR- Instrument Flight Rules

Rules and regulations established by the ICAO (International Civil Aviation Organization) and the national regulatory authorities to govern the flight rule conditions in which the flight by outside visual reference is not safe. IFR governs the flight of aircraft along controlled airways and airports, and aircraft separation is controlled by the operators from the ground. Flight according to instrument flight rules is done by reference to instruments in the cockpit; the aircraft is navigated by reference to electronic signals. For flying under IFR, aircraft shall be equipped with suitable instruments and with navigation equipment appropriate to the route to be flown. An IFR flight shall not normally be operated over high terrain or in mountainous areas at a level less than 2000 ft (600 m) above the highest obstacle located within 5 miles (8 km) of the estimated position of the aircraft. In areas other than these, the minimum flight level shall be at least 1000 ft (300 m) above the highest obstacle within 5 miles (8 km) of the estimated position of the aircraft.