A pneumatic or air-filled tire is composed on an inner core which is filled with pressurized air and sealed airtight. Usually, a reinforced steel belted tread or other materials, provides the contact part with the road and seals this inner core.
The tire would remain inflated with all the weight of the vehicle resting on it, because the pressure of the air within the tire is greater than atmospheric air pressure. The air pressure inside the tire gives resistance against forces which attempt to deform the tire. When the tire hits bumps in the road, this gives the tire a slight degree of a cushioning effect. If you have experienced taking a ride in an old-fashioned carriage that had wooden wheels, you know how big of a difference a set of pneumatic tires makes.
Of course, there are some disadvantages to pneumatic tires. For instance in highly dangerous applications or high-performance situations, these tires could suffer a puncture and this will result in a complete failure. The consequence of a blowout at high speeds can result in a serious car crash. Military planners must take into account tires getting blown out by gunfire or explosion shrapnel. A vehicle crew's worst nightmare is becoming trapped in a fire zone due to all of their tires becoming flat. Airless tires obviously don't suffer from these kind of problems and therefore, can be more suitable in some applications.
Pneumatic tires have one more issue involving variations in air pressure and tire performance. Lower tire pressure can create improved traction and increased comfort. This is due to the fact that tires flatten slightly and more tread is placed in contact with the road. The air pressure inside of the tire works to maintain the "up and down" stiffness as well as maintain the lateral stiffness of the tire. Hence, less air pressure allows the tires' sidewalls to flex. Unfortunately, this leads to poor handling. In an airless tire, the stiffness in those two dimensions is independent.
There are other issues with air pressure. Customers are notoriously unreliable when it comes to maintaining correct air pressure. Tires which have wrong air pressure could lead to unsafe situations. It is very vital to keep in mind that pneumatic tires are prone to temperature changes too, that can be responsible for changing the internal pressure of the tire. It is vital to consider the type of environments you would be needing your machinery to function in so that you can check the tires on a regular basis and keep the machine as safe as possible.