I was taught how to bevel, and make sharp edges for different areas of an object. To bevel, I had to make more divisions, which many more polygons. It helped make a smoother/sharper edges to make the object more life-like inside of the super sharp edges.

https://app.pluralsight.com/player?course=maya-2017-introduction-2535&author=justin-marshall&name=maya-2017-introduction-2535-m3&clip=7&mode=live