What is the difference between Sealed and Constant Airflow Inflatables ？

While most inflatables tend to be continuously inflated by a blower system that keeps them from deflating, 
airtight  inflatables (sometimes called "sealed inflatables") are becoming more and more common. 

So, what are the differences between the two? 

When a continuous air blower feeds an inflatable with air, it is considered a continuous inflatable or a cold-air inflatable. It is simply plugged in, installed/placed in your area of choice and then secured with ropes (for safety reasons).  
Continuous blower type of inflatables utilize single layer construction where a single layer of material is sewn together forming the exterior inflatable shell. Since there is only a single layer that is sewn, air escapes through the seams, which is why constant inflation is required. 

Whereas airtight or sealed inflatables utilize dual layer construction, which has an exterior shell similar to the cold-air types, but also contain an airtight internal bladder that is sealed with a valve. These sealed inflatables only require electricity when inflating with an external inflator, which is provided with every airtight inflatable purchase. 

Cold-air models need to be plugged in at all times. Large structures are almost always continuous blower types. The sealed inflatable is only inflated once, like a beach ball, and it doesn't require you to have a blower system constantly filling it with air. So, once it is inflated all you need to do is seal the air valve that is often located somewhere inconspicuous, and you're done.