"Carry-On" is a term commonly used in travel to refer to luggage that passengers can bring onto an airplane without checking it in. This type of bag is typically smaller and must meet specific size and weight restrictions set by airlines. Carry-on bags allow travelers to keep their belongings close and avoid the hassle of lost luggage. In addition to bags, the term "carry-on" can also refer to the items inside, such as personal electronics, clothing, and toiletries. Passengers should be aware of security regulations regarding liquids and prohibited items to ensure a smooth boarding process.