Classification 

Although most UAVs are fixed-wing aircraft, rotorcraft designs (i.e., RUAVs) such as this MQ-8B Fire Scout are also used.

UAVs typically fall into one of six functional categories (although multi-role airframe platforms are becoming more prevalent):

• Target and decoy – providing ground and aerial gunnery a target that simulates an enemy aircraft or missile
• Reconnaissance – providing battlefield intelligence
• Combat – providing attack capability for high-risk missions (see Unmanned combat air vehicle)
• Logistics – delivering cargo
• Research and development – improve UAV technologies
• Civil and commercial UAVs – agriculture, aerial photography, data collection

The U.S. Military UAV tier system is used by military planners to designate the various individual aircraft elements in an overall usage plan.

Schiebel S-100 fitted with a Lightweight Multirole Missile

Vehicles can be categorised in terms of range/altitude. The following has been advanced  as relevant at industry events such asParcAberporth Unmanned Systems forum:

• Hand-held 2,000 ft (600 m) altitude, about 2 km range
• Close 5,000 ft (1,500 m) altitude, up to 10 km range
• NATO type 10,000 ft (3,000 m) altitude, up to 50 km range
• Tactical 18,000 ft (5,500 m) altitude, about 160 km range
• MALE (medium altitude, long endurance) up to 30,000 ft (9,000 m) and range over 200 km
• High-Altitude Long Endurance (high altitude, long endurance – HALE) over 30,000 ft (9,100 m) and indefinite range
• Hypersonic high-speed, supersonic (Mach 1–5) or hypersonic (Mach 5+) 50,000 ft (15,200 m) or suborbital altitude, range over 200 km
• Orbital low earth orbit (Mach 25+)
• CIS Lunar Earth-Moon transfer
• Computer Assisted Carrier Guidance System (CACGS) for UAVs

U.S. UAV demonstrators in 2005

Other categories include: 

• Hobbyist UAVs – which can be further divided into
  • Ready-to-fly (RTF)/Commercial-off-the-shelf (COTS)
  • Bind-and-fly (BNF) – that require minimum knowledge to fly the platform
  • Almost-ready-to-fly (ARF)/Do-it-yourself (DIY) – that require significant knowledge to get in the air.
• Midsize military and commercial drones
• Large military-specific drones
• Stealth combat drones

Classifications according to aircraft weight are quite simpler:

• Micro air vehicle (MAV) – the smallest UAVs that can weight less than 1g.
• Miniature UAV (also called SUAS) – approximately less than 25 kg.
• Heavier UAVs.