Baggage allowance refers to the maximum weight and number of bags that a passenger can bring on a flight without incurring extra fees. Airlines typically specify these limits based on the travel class, destination, and ticket type. For example, economy class passengers may have a lower allowance compared to those in business class. Each airline has its own rules regarding baggage size and weight, so it's important for travelers to check their specific airline's policy before packing. Exceeding the baggage allowance can result in additional charges, which can vary significantly between different airlines.