General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services for other purposes.  However, for statistical purposes ICAO uses a definition of general aviation which includes aerial work. 
The International Civil Aviation Organization (ICAO) defines civil aviation aircraft operations in three categories: General Aviation (GA), Aerial Work (AW) and Commercial Air Transport (CAT).   Aerial work operations are separated from general aviation by ICAO by this definition. Aerial work is when an aircraft is used for specialized services such as agriculture, construction, photography, surveying, observation and patrol, search and rescue, and aerial advertisement. However, for statistical purposes ICAO includes aerial work within general aviation, and has proposed officially extending the definition of general aviation to include aerial work, to reflect common usage.   The proposed ICAO classification includes instructional flying as part of general aviation (non-aerial-work).
The International Council of Aircraft Owner and Pilot Associations (IAOPA) refers to the category as general aviation/aerial work (GA/AW) to avoid ambiguity. Their definition of general aviation includes: 
IAOPA's definition of aerial work includes, but is not limited to: 
Commercial air transport includes:
However, in some countries, air taxi is regarded as being part of GA/AW.
Private flights are made in a wide variety of aircraft: light and ultra-light aircraft, sport aircraft, homebuilt aircraft, business aircraft (like private jets), gliders and helicopters.  Flights can be carried out under both visual flight and instrument flight rules, and can use controlled airspace with permission.
In 2003, the European Aviation Safety Agency was established as the central EU regulator, taking over responsibility for legislating airworthiness and environmental regulation from the national authorities. 
Of the 21,000 civil aircraft registered in the United Kingdom,  96 percent are engaged in GA operations, and annually the GA fleet accounts for between 1.25 and 1.35 million hours flown. There are 28,000 private pilot licence holders, and 10,000 certified glider pilots. Some of the 19,000 pilots who hold professional licences are also engaged in GA activities. GA operates from more than 1,800 airports and landing sites or aerodromes, ranging in size from large regional airports to farm strips.
General aviation is particularly popular in North America, with over 6,300 airports available for public use by pilots of general aviation aircraft (around 5,200 airports in the U.S. and over 1,000 in Canada ). In comparison, scheduled flights operate from around 560 airports in the U.S.  According to the U.S. Aircraft Owners and Pilots Association, general aviation provides more than one percent of the United States' GDP, accounting for 1.3 million jobs in professional services and manufacturing. 
Most countries have a civil aviation authority that oversees all civil aviation, including general aviation, adhering to the standardized codes of the International Civil Aviation Organization (ICAO).
Aviation accident rate statistics are necessarily estimates. According to the U.S. National Transportation Safety Board, general aviation in the United States (excluding charter) suffered 1.31 fatal accidents for every 100,000 hours of flying in 2005, compared to 0.016 for scheduled airline flights.  In Canada, recreational flying accounted for 0.7 fatal accidents for every 1000 aircraft, while air taxi accounted for 1.1 fatal accidents for every 100,000 hours.  More experienced GA pilots appear generally safer, although the relations between flight hours, accident frequency, and accident rates are complex and often difficult to assess.   
A small number of commercial aviation accidents in the United States have involved collisions with general aviation flights, notably TWA Flight 553, Piedmont Airlines Flight 22, Allegheny Airlines Flight 853, PSA Flight 182 and Aeroméxico Flight 498.