A compound microscope is called that because it uses two or more lenses to magnify an object.

Here's the breakdown:

* "Compound" refers to the combination of multiple elements.

* "Microscope" means an instrument for viewing tiny objects.

The two main lenses in a compound microscope are:

1. Objective lens: This lens is located near the object being viewed and provides the initial magnification.

2. Eyepiece lens: This lens is located at the top of the microscope and further magnifies the image from the objective lens.

By using multiple lenses, a compound microscope can achieve much higher magnification than a simple microscope (which only uses one lens). This allows us to see objects that are too small to be seen with the naked eye, like cells, bacteria, and other microscopic structures.