An Aerial lift is any vehicle-mounted device used to elevate personnel, including: 

• Extendable boom platforms
• Aerial ladders
• Articulating (jointed) boom platforms,
• Vertical towers, and
• Any combination of the above.

Aerial lifts have replaced ladders and scaffolding on many job sites due to their mobility and flexibility. They may be made of metal, fiberglass reinforced plastic, or other materials.  They may be powered or manually operated, and are considered to be aerial lifts whether or not they can rotate around a primarily vertical axis.