Air mattresses are a type of sleeping pad typically used on camping trips. About as similar as you can get to sleeping on standard mattress while out in the wilderness, air mattresses easily accommodate sheets, blankets, and other bedding.
Pumps are generally used to fill air mattresses. Surprisingly heavy considering they’re full of air, these types of sleeping pads are also a bit bulky. Because they’re nevertheless so very comfortable, it’s best to use them on car, boating, and hunting trips. It’s rather difficult to bring them on a backpacking excursion, as there’s the pump to haul around in addition to the mattress, no matter how neatly it folds up when deflated.
While comfortable as all heck, air mattresses don’t provide a whole lot of insulation. As the night colder, the air in the mattress also gets colder, now you find your self sleeping on some pretty darn-cold air. This makes them ideal for warm weather car camping trips and the like, as they won’t help keep you warm while sleeping on the side of a mountain in winter.
Another minus to dealing with air mattresses is the risk of puncture. Pretty much anything that inflates runs the risk of puncturing and ripping, but as long as you take good care of your mattress and carefully inspect where you intend to place it, you’ll be in good shape.