What is the excavator machine? a large, powerful machine with a container connected to a long arm, used for digging up the ground. What do you use an excavator for? In simple terms, excavators are large industrial machines used to move large amounts of material, like rock and soil. That means they do everything from digging a basement to laying pipe to mining. What is excavators and loaders? Wheel loaders and excavators both have different functions. An excavator is designed to dig up dirt while a wheel loader moves materials around easily onsite. The key difference between these two machines lies in their primary purpose.