A captive balloon is a type of inflated balloon which is tethered to the ground or a stationary object. Similar to a tethered balloon, it is used for various purposes such as for aerial photography, sightseeing, surveillance, or advertising. There are various synonyms for a captive balloon, including observation balloon, tethered aerostat, aerial balloon, captive blimp, and tethered blimp. Each of these terms describes the same concept, specifically, a large, inflatable balloon that is anchored to the ground and used for a specific purpose. Whether you refer to it as an observation balloon or a captive blimp, its function remains the same: to provide a view from above.