An extension ladder is a type of ladder that can be adjusted to different heights. It consists of two or more sections that slide past each other, allowing the user to extend or retract the ladder as needed. Extension ladders are commonly made of materials like aluminum or fiberglass, making them lightweight yet sturdy. These ladders are often used for tasks that require reaching high places, such as painting, cleaning gutters, or accessing roofs. Safety features, like rubber feet and locking mechanisms, help ensure stability while in use. Proper setup and usage are essential to prevent accidents.