The detailed properties of the returned object can be found in the documentation of the Airport data model.
{"icao":"KJFK","iata":"JFK","localIdentifier":"JFK","name":"John F. Kennedy International ","servedCity":"New York","servedCityGoverningDistrict": {"code":"US-NY","name":"New York","administrativeType":"State" },"administrativeCity":null,"administrativeCityGoverningDistrict":null,"elevation":3.96,"coordinates": {"latitude":40.6399278,"longitude":-73.7786944 },"variation":-13.00,"country": {"iso2":"US","iso3":"USA","isoNumeric":840,"name":"United States","officialName":"United States of America","localIdentifierName":null },"timeZone":"America/New_York","perimeter":null,"type":"AIRPORT","operator":"PUBLIC","accessibleFor": ["SCHEDULED","NON_SCHEDULED","GENERAL_AVIATION","MILITARY","BUSINESS_AVIATION" ],"ifr":true,"nonScheduledPermission":"NONE","nonScheduledPermissionNotes":null,"mandatoryHandling":false,"mandatoryQualification":false,"qualificationLink":null,"qualificationNotes":null,"weightLimit":9999999.00,"wingspanLimit":999.00,"paxLimit":999,"referenceWeatherStation":null,"aid":"APT-KS1J-8E0L"}
{"error":"The Airport identified by {AID} does not exist.","timestamp":"2022-07-14T11:45:53.093205678Z","status":404,"message":"The Airport identified by {AID} does not exist.","path":"/airports/{AID}"}
Retrieving airport data by ICAO, IATA and local identifiers is also possible, for more information view Free airport endpoints.