In comparison, Autodesk Maya had a normals modifier tool in the toolbar which you could select Soften Edge or Harden Edge. Soften Edge would make edges render up to 180 degrees giving it a smooth look without adding any meshes/geometry. I've tried searching many tutorials about Blender how to simply mark any selected edge to appear smooth, but it goes into some crazy process involving smooth all then edge modifiers/bevel steps which actually adds geometry overall.
This video shows what I'm trying to do in Blender, does Blender have anything as easy to mark edges smooth/hard?: https://www.youtube.com/watch?v=vOoZ-wvGmrQ