Here's why:

* Robert Hooke, the scientist credited with discovering cells, used a compound microscope in 1665.

* A compound microscope uses multiple lenses to magnify the image, providing a much higher magnification than a simple microscope.

* This allowed Hooke to see the tiny compartments within a piece of cork, which he named "cells."

While other types of microscopes exist, the compound light microscope was crucial to the groundbreaking discovery of the fundamental building blocks of life.