Carry-on baggage refers to the small luggage that passengers are allowed to bring onto an aircraft. This type of baggage typically includes items like backpacks, suitcases, or duffel bags that fit in the overhead compartment or under the seat in front of you. Airlines often have specific size and weight restrictions for carry-on items, which can vary by carrier. Passengers use carry-on baggage to keep essential items close during their flight, such as clothing, toiletries, and electronics. It allows for easier access to personal belongings without the need to check a bag, which can save time at the airport and reduce the risk of lost luggage.