As you can notice from the suggested products, as well as the previously explained features that a mattress could possess, there are several types of mattresses and each one works on different principles. For instance, the self-inflating air mattresses are working together with a valve, or several valves, that are responsible for the inflation and deflation process. Since they are self-inflating, the air is pretty much sucked in or thrown outside through the one-way valve and you are good to go.
However, the self-inflating mattresses are much different than the ones that require a pump to do the inflation and deflation process. These camping mattresses come with a pump or it is sold separately. However, you cannot inflate the mattress without one. The pumps could run on batteries, which would additionally require that you purchase batteries, or they could work with a power source. Regardless of the power source type, the pump will take care of the inflation and deflation process for you and it will only take about five minutes. Although this is quite impressive, remember that the pump is adding extra weight which is not too pleasant if you should walk to your campsite.