Excavator

An Excavator (sometimes called a digger) is a piece of heavy construction equipment. Excavators are used to dig in the ground or to move large objects. At the base of the machine, it usually has two tracks to move it. Above the tracks is a platform that rotates (180° or 360° degrees). The operator sits in a cab and controls the excavator. One set of controls moves the machine forward and backward. Another set of controls operates the arm and the tilting bucket. hydraulic fluid, hydraulic cylinders and hydraulic motors control the machine. 
It is characterized by its four main parts.
Bucket - Also called a scoop, this part is used to take out a huge chunk of soil from the ground. It is made of solid steel and has large teeth to make scooping easier. 
Excavators come in different sizes based on the type of work they do. Some are cable-operated excavators. Some also use wheels instead of tracks. There are many types of excavator: