Why does a bench grinder have two wheels?

A bench grinder has two wheels to provide versatility for various grinding tasks. Each wheel can have a different grit or type, allowing users to sharpen tools, grind metal, or shape materials depending on their needs. Additionally, using two wheels can enhance efficiency, as one wheel can be used for rough grinding while the other is reserved for finer finishing. This dual-wheel design helps achieve a smoother and more precise finish on workpieces.