An airport is a special type of aerodrome that has achieved the criteria for certification by the International Civil Aviation Organisation (ICAO) or ICAO’s regulatory requirements
According to the ICAO an aerodrome is "A defined area on land or water (including any buildings, installations, and equipment) intended to be used either wholly or in part for the arrival, departure, and surface movement of aircraft."
In short, aerodromes are places where flight operations can take place and can include an isolated airstrip to a commercial airport.