A "stopover" refers to a planned break in a journey, typically during air travel. It occurs when a traveler has a layover at an airport for more than 24 hours on international flights or more than 4 hours on domestic flights. This allows passengers to leave the airport and explore the city or country where they are stopping before continuing to their final destination. Stopovers can be beneficial for travelers, as they provide an opportunity to visit new places without the need for a separate trip. Airlines often offer stopover programs, allowing passengers to book flights that include extended layovers in cities like Iceland's Reykjavik or Singapore, making travel more enjoyable and enriching.