Air tools use pneumatic systems. These systems compress the surrounding air and pump it into chambers until it is released by the tool, providing a sudden, sharp burst of force. This force is used for many different locations, and is recharged by the air compressor as the compressed air is used. While compression systems must be connected to the air compressor, they do not usually need to be plugged into an outlet or use batteries.
Speed
Air tools like pneumatic drills and nail guns are often lauded for their speed. The air chambers they use recharge very quickly and a skilled laborer can use air-based devices to accomplish jobs more quickly than electric versions. However, tools that must be used for long periods of time can benefit from purely electrical systems, since air compressors sometimes need time to recharge or cool down.
Cost
Pneumatic systems require more components and tend to cost more than electrical versions of the same tools, but there is a lot of variance. However, after the initial investment of the air compressor and required tubing, prices for pneumatic tools cost less than the complete electrical versions.
Maintainence
Electrical tools require maintenance to ensure their motors are operating efficiently. Many professionals take apart their electrical tools about once every year to clean them and replace any worn parts. Pneumatic tools also wear out, but they tend to do so more slowly than the electrical versions and do not need to be totally replaced as often. Pneumatic versions also need less daily maintenance, since they tend to become jammed with construction material less easily.
Portability
Electrical tools can be battery powered, which allows them to be used in locations where using pneumatic tools may be difficult. On the other hand, the hand-held components of pneumatic tools are lighter and easier to carry, so as long as they are within reach of the compressor they can be easier to manipulate in the field.
Benefits of using pneumatic (air) vs. electrical tool