What is the crane arm called?

The crane arm is typically called the boom.

However, depending on the type of crane and its specific function, other terms may be used:

* Jib: This term is often used for the horizontal arm extending from the main boom.

* Luffing boom: This refers to a boom that can be adjusted in length or angle.

* Telescopic boom: This describes a boom that can be extended or retracted, like a telescope.

So, while "boom" is the most common and general term, it's good to consider the context and specific crane type when referring to the arm.