Air cargo is any property carried or to be carried in an aircraft. Air cargo comprises air freight, air express and airmail.

Air combat manoeuvring (also known as ACM or dogfighting) is the tactical art of moving, turning and/or situating one's fighter aircraft in order to attain a position from which an attack can be made on another aircraft. Air combat manoeuvres rely on offensive and defensive basic fighter manoeuvring (BFM) to gain an advantage over an aerial opponent.

An air compressor is a device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure. When tank pressure reaches its upper limit the air compressor shuts off. The compressed air, then, is held in the tank until called into use. The energy contained in the compressed air can be used for a variety of applications, utilizing the kinetic energy of the air as it is released and the tank depressurizes. When tank pressure reaches its lower limit, the air compressor turns on again and re-pressurizes the tank. An air compressor must be differentiated from an air pump which merely pumps air from one context (often the surrounding environment) into another (such as an inflatable mattress, an aquarium, etc.). Air pumps do not contain an air tank for storing pressurized air and are generally much slower, quieter, and less expensive to own and operate than an air compressor.

Air conditioning (often referred to as AC, A.C., or A/C) is the process of removing heat from the interior of an occupied space, to improve the comfort of occupants. Air conditioning can be used in both domestic and commercial environments. This process is most commonly used to achieve a more comfortable interior environment, typically for humans or animals; however, air conditioning is also used to cool/dehumidify rooms filled with heat-producing electronic devices, such as computer servers, power amplifiers, and even to display and store artwork. Air conditioners often use a fan to distribute the conditioned air to an occupied space such as a building or a car to improve thermal comfort and indoor air quality. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants (chemicals which remove moisture from the air) and subterraneous pipes that can distribute the heated refrigerant to the ground for cooling. In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, cooling, (de-)humidification, cleaning, ventilation, or air movement). In common usage, though, "air conditioning" refers to systems which cool air. In construction, a complete system of heating, ventilation, and air conditioning is referred to as heating, ventilation, and air conditioning (HVAC – as opposed to AC).

Air currents are concentrated areas of winds. They are mainly due to differences in pressure and/or temperature. They are divided into horizontal and vertical currents: both are present at mesoscale while horizontal ones dominate at synoptic scale. Air currents are not only found in the troposphere, but extend to the stratosphere and mesosphere.

An air flow meter, is a device that measures air flow, i.e. how much air is flowing through a tube. It does not measure the volume of the air passing through the tube, it measures the mass of air flowing through the device per unit time. Thus air flow meters are simply an application of mass flow meters for a special medium. Typically, mass air flow measurements are expressed in the units of kilograms per second (kg/s).

An air gun (or airgun) is any kind of gun that launches projectiles pneumatically with compressed air or other gases that are pressurized mechanically without involving any chemical reactions, in contrast to a firearm, which pressurizes gases chemically via an exothermic oxidation (deflagration) of combustible propellants which generates propulsive energy by breaking molecular bonds. Both the long gun and handgun forms (air rifle and air pistol) typically propel metallic projectiles, that are either diabolo-shaped pellets, or spherical shots called BBs. Certain types of air guns (usually rifles) may also propel darts or arrows. The first air guns were developed as early as the 1500s. They have been used in hunting, sporting and warfare. Modern air guns use one of three types of power source depending on the design: spring-piston, pneumatic, and bottled compressed gas (most commonly carbon dioxide).

An air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system. An air handler is usually a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers. Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU. Sometimes AHUs discharge (supply) and admit (return) air directly to and from the space served without ductwork. Small air handlers, for local use, are called terminal units, and may only include an air filter, coil, and blower; these simple terminal units are called blower coils or fan coil units. A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU). An air handler designed for outdoor use, typically on roofs, is known as a packaged unit (PU) or rooftop unit (RTU).

An air horn is a pneumatic device designed to create an extremely loud noise for signaling purposes. It usually consists of a source which produces compressed air, which passes into a horn through a reed or diaphragm. The stream of air causes the reed or diaphragm to vibrate, creating sound waves, then the horn amplifies the sound making it louder. Air horns are widely employed as vehicle horns, installed on large semi-trailer trucks, fire trucks, trains, and some ambulances as a warning device, and on ships as a signaling device.

An air pump is a device for pushing air. Examples include a bicycle pump, pumps that are used to aerate an aquarium or a pond via an airstone; a gas compressor used to power a pneumatic tool, air horn or pipe organ; a bellows used to encourage a fire; a vacuum cleaner and a vacuum pump. Pumps and compressors use very similar mechanisms, and basically perform the same action, but in different fluid regimes. At some point there is a crossover point in terminology, but here are some stereotypes: • Compressors operate on compressible fluids, typically gases. Pumps operate on fluids, typically liquids, approximated as incompressible. • Compressors are intended to develop a very high pressure rise against a closed system; pumps are designed to develop relatively little pressure against a free-flowing system with minimal backpressure. • Pumps are often used in continuous-flow operation, while many lower-end compressors must have intermittent duty cycles. • Compressors usually have a feedback sensor to shut off when they reach a desired pressure; pumps have a fixed design and operate freely across their performance curve as conditions change