A pneumatic or air-filled tire is composed on an inner core which is filled with pressurized air and sealed airtight. Normally, a reinforced steel belted tread or other materials, provides the contact area with the road and seals this inner core.
As the pressure of the air within the tire is more than atmospheric air pressure, the tire remains inflated even with the weight of the vehicle resting on it. The pressure of the air in the tire provides resistance against forces that 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 understand exactly how huge of a difference a set of pneumatic tires makes.
Of course, there are some drawbacks to pneumatic tires. Like for example in highly dangerous applications or high-performance situations, these tires can suffer a puncture and this would lead to a complete failure. The consequence of a blowout at high speeds could lead to a dangerous car crash. Military planners must consider tires getting blown out by gunfire or explosion shrapnel. The worst nightmare of a vehicle crew is becoming trapped in a fire zone because of all of their tires becoming flat. Airless tires evidently don't suffer from these issues and thus, might be more suitable in certain applications.
Pneumatic tires have one more issue involving variations in air pressure and tire performance. Lower tire pressure could create increased comfort and improved traction. This is due to the fact that tires flatten slightly and more tread is placed in contact with the road. The air pressure in the tire works to maintain the "up and down" stiffness as well as maintain the lateral stiffness of the tire. Therefore, reduced air pressure enables the sidewalls of the tires to flex. This results in poor handling unfortunately. In an airless tire, the stiffness in those two dimensions is independent.
Air pressure factors into other issues also. When it comes to maintaining correct air pressure, consumers are notoriously undependable. Improper air pressure within tires could result in very unsafe situations. It is important to keep in mind that pneumatic tires are susceptible to temperature changes also, which can be responsible for changing the internal pressure of the tire. It is important to take into consideration the type of environments you would be requiring your equipment to operate in so that you could frequently check the tires and keep the machinery as safe as possible.