Civil aviation is one of two major categories of flying, representing all non-military aviation, both private and commercial. Most of the countries in the world are members of the International Civil Aviation Organization (ICAO) and work together to establish common standards and recommended practices for civil aviation through that agency.

Civil aviation includes two major categories:

Scheduled air transport, including all passenger and cargo flights operating on regularly scheduled routes; and
General aviation (GA), including all other civil flights, private or commercial.

Although scheduled air transport is the larger operation in terms of passenger numbers, GA is larger in the number of flights (and flight hours, in the U.S.[1]) In the U.S., GA carries 166 million passengers each year, more than any individual airline, though less than all the airlines combined. Since 2004, the US Airlines combined have carried over 600 million passengers each year, and in 2014, they carried a combined 662,819,232 passengers.

Some countries also make a regulatory distinction based on whether aircraft are flown for hire like:

Commercial aviation includes most or all flying done for hire, particularly scheduled service on airlines; and
Private aviation includes pilots flying for their own purposes (recreation, business meetings, etc.) without receiving any kind of remuneration.

A British Airways Boeing 747-400 departs London Heathrow Airport. This is an example of a commercial aviation service.
All scheduled air transport is commercial, but general aviation can be either commercial or private. Normally, the pilot, aircraft, and operator must all be authorized to perform commercial operations through separate commercial licensing, registration, and operation certificates.