Travel & Flight Glossary
Plain-language definitions of flight booking, baggage, fare, airport and visa terms — everything you need to search, book and fly with total confidence.
Booking
Change FeeCodeshareDirect Flight vs Nonstop FlightDry LeaseDuplicate BookingE-TicketFare HoldFlight NumberGlobal Distribution System (GDS)Group BookingHidden-City TicketingInterline AgreementMarried SegmentsMetasearch EngineName Correction vs Name ChangeNDC (New Distribution Capability)New Distribution Capability (NDC)No-ShowOnline Travel Agency (OTA)Open-JawOverbooking (Denied Boarding)PNR (Passenger Name Record)Same-Day Flight ChangeSchedule ChangeSelf-TransferSplit TicketingFlying StandbyStopoverTicketed vs ConfirmedTicketing Time Limit (TTL)24-Hour Refund RuleWaitlist (Booking)Wet Lease (ACMI)
Fares & Prices
Advance-Purchase RequirementAncillary RevenueBack-to-Back TicketingBasic EconomyBid UpgradeBranded FaresCompanion FareConsolidator FareDynamic PricingError FareFare Basis CodeFare Bucket (Booking Class)Fare DifferenceFare RulesFlight CreditFuel Surcharge (Carrier-Imposed Surcharge)Infant and Child FaresLow-Cost CarrierMinimum Stay RequirementNet FareOne-Way vs Return PricingPremium EconomyPrice Match GuaranteeRefundable FareSaturday-Night StaySeat Selection FeeTaxes and FeesTax Refund on an Unused TicketYield Management
Baggage
Baggage AllowanceBaggage EmbargoBaggage Liability LimitBaggage PoolingBaggage Sizer (Cabin Bag Gauge)Baggage TagBaggage TracingCarry-On BaggageChecked BaggageDangerous Goods in BaggageDuty-Free AllowanceExcess BaggageFragile and Special BaggageGate CheckInterline Baggage TransferLeft Luggage (Baggage Storage)Linear Dimensions (Sum of Three Sides)Liquids Rule (100 ml)Lost Baggage and the PIRCarrying Mobility EquipmentMusical Instrument BaggageOversized BaggagePersonal ItemTravelling with a Pet in the CabinPiece Concept vs Weight ConceptPower Banks & Lithium BatteriesSealed Tamper-Evident Bag (STEB)Smart Luggage Battery RuleSporting Equipment BaggageThrough-Checked Baggage
Airport & Transit
Airport SlotAirport TransferTransitAirside vs LandsideAutomated Border Gates (e-Gates)Bag DropBaggage ReclaimBoarding GateBoarding GroupBoarding PassBus Boarding (Remote Stand)Check-in Cut-offConnecting FlightCurbside Check-InDe-icingFast Track SecurityFlight Information Display System (FIDS)Gate ClosureHold Baggage ScreeningIATA vs ICAO CodesJet BridgeLayoverLong-Stay Airport ParkingAirport Lost and FoundMinimum Connection Time (MCT)Night Flight CurfewPreclearancePriority BoardingRemote StandRunway DesignatorSelf-Service Check-In KioskSpecial Assistance RequestTerminal TransferTrusted Traveller Programme
Loyalty & Miles
Air Miles (Mileage)Airline AllianceAward AvailabilityAward ChartAward Fuel SurchargeAward Redeposit FeeAward StopoverAward TicketCo-Branded Credit CardCompanion VoucherElite Bonus MilesElite StatusFamily PoolingFrequent-Flyer ProgramLifetime StatusAirport Lounge AccessMileage DevaluationMileage Upgrade AwardMiles ExpirationPoints Plus CashPoints TransferPoints ValueQualifying MilesSaver AwardSoft LandingStatus Match
Visa & Entry
Arrival CardBusiness VisaCash Declaration LimitRed and Green ChannelsDigital Nomad VisaE-VisaElectronic Travel Authorization (ETA/ESTA)Entry/Exit System (EES)ETIAS (European Travel Information and Authorisation System)Golden VisaK-ETA (Korea Electronic Travel Authorization)Multiple-Entry Visa90/180 RuleOnward TicketPassport Validity Rule (Six-Month Rule)Port of EntryResidence PermitSchengen AreaSecondary InspectionSingle-Entry VisaTourist VisaTransit VisaVisa-Free TravelVisa on ArrivalVisa OverstayVisa Waiver Program (VWP)
In-Flight
Airplane Ear (Ear Barotrauma)Flight Mode RuleBassinet Seat (Sky Cot)Bulkhead SeatCabin Air RecirculationCabin ClassCabin Humidity and HydrationCabin PressureDeep Vein Thrombosis (DVT) and Air TravelExit Row SeatGalleyIn-Seat PowerInflight Entertainment (IFE)In-Flight Wi-FiJet LagLie-Flat SeatMotion Sickness in FlightNarrowbody vs WidebodyOverhead BinRed-Eye FlightSeat ConfigurationSeat PitchSpecial Meal RequestTurbopropTurbulenceUnaccompanied MinorWake Turbulence
Car Rental
Additional Driver FeeChild Seat RentalCollision Damage Waiver (CDW)Cross-Border Fee & PermitRenting a Car with a Debit CardElectronic Toll ChargeExcess Reduction (Super CDW)Fair Wear and TearFull-to-Full Fuel PolicyInternational Driving Permit (IDP)Loss Damage Waiver (LDW)Mileage CapMotorway VignetteOff-Airport Rental LocationOne-Way Rental FeeOut-of-Hours Fee (After-Hours Pickup)Pre-Existing Damage ReportACRISS Car CodeRental Return Grace PeriodSecurity Deposit (Pre-authorisation Hold)Uninsured Parts (Tyres, Glass, Undercarriage)Unlimited MileageWinter Tyre RequirementYoung Driver Surcharge
Delays & Disruptions
Aircraft Swap (Equipment Change)Airline Strike DisruptionAirspace ClosureATC Slot (CTOT)Bird StrikeDeadline to Claim CompensationCrew Duty Time LimitDenied Boarding CompensationDuty of CareEU261 (Air Passenger Rights)Extraordinary Circumstances (Force Majeure)Flight Delay CompensationFlight DiversionGo-AroundGround StopHolding PatternInvoluntary DowngradeInvoluntary RefundIrregular Operations (IROP)Mechanical DelayMinimum Equipment List (MEL)Misconnection (Missed Connection)Montreal ConventionReaccommodationRerouting (Rebooking After Disruption)Tarmac DelayTravel Waiver (Weather Waiver)Weather Delay
Travel Documents
APIS (Advance Passenger Information)ApostilleBiometric Passport (e-Passport)Certified TranslationConsular ServicesDamaged PassportDiplomatic PassportDual Citizenship TravelEmergency Travel DocumentInadmissible Passenger (INAD)Invitation LetterMachine-Readable Passport (MRZ)Medical Clearance (MEDIF)Child Travel Consent LetterMobile Boarding PassTravelling on a National ID CardNotarized Travel DocumentPassport Blank PagesPassport Photo RequirementsPassport RenewalProof of AccommodationProof of FundsTimatic Document CheckVaccination CertificateYellow Fever Certificate (Yellow Card)
Travel Insurance
Adventure Sports CoverageAnnual Multi-Trip InsuranceBaggage Delay CoverageBaggage Loss CoverageCancel For Any Reason (CFAR)Credit Card Travel InsuranceEmergency Assistance HotlineGeographical Cover ZonesGovernment Travel AdvisoryWaiting Period (Travel Insurance)Medical Evacuation InsuranceMedical RepatriationMissed Departure CoverPersonal Liability CoverPolicy Excess (Deductible)Policy Wording and Policy SchedulePre-Existing Medical ConditionPrimary vs. Secondary CoverageScheduled Airline Failure CoverSchengen Travel Medical InsuranceSingle-Trip InsuranceTrip Cancellation InsuranceTrip Curtailment (Cutting Your Trip Short)Trip Delay CoverageTrip Interruption Insurance
Payments & Fees
Agency Service FeeBuy Now, Pay Later for Travel (BNPL)Card Authorization HoldCard on FileChargebackCredit Card SurchargeCurrency Conversion Markup (FX Markup)Declined Card at BookingHotel Deposit RequirementDigital Wallet PaymentDynamic Currency Conversion (DCC)Foreign Transaction FeeInstallment Payment (Taksit)Merchant of RecordMir Payment SystemPay by Bank (Open Banking Transfer)Payment Card VerificationFraud Review HoldPayment GatewayPrepaid Travel CardRefund Processing TimeSplit Payment (Multiple Cards)3-D Secure (Online Card Verification)Two-Factor Authentication (Travel Payments)Virtual Card for Travel Booking
Trip Planning
Best Time to Book FlightsBlock TimeBooking Window Sweet SpotCarbon Offsetting a FlightDaylight Saving Time ChangeETOPSFifth Freedom FlightFlexible-Date SearchFree Stopover ProgramGreat Circle RouteHub-and-Spoke NetworkIncognito Browsing for FlightsInternational Date LineJet StreamLayover vs. StopoverMileage RunMulti-City ItineraryNearby Airport SearchOff-Peak Travel WindowOvernight ConnectionPositioning FlightPrice AlertRound-the-World TicketSeasonal RouteShoulder SeasonSustainable Aviation Fuel (SAF)Turnaround TimeVirtual Interlining