Weird, smooth edges

I’m not really all that experienced at 3D modeling, and usually only use it for low poly stuff, but recently I noticed that Meta Ellipsoids and Meta Cubes and the like all have smooth-looking edges. Upon converting them to Meshes and editing them in edit mode they look like any other mesh, but they still have smooth edges that I can’t seem to replicate any other way.

This is what I’m talking about:

They both have the same vertices but one has smooth edges, and I can’t figure out why.

Meh. I need to read first.

Click ‘Set Smooth’ option under the Editing buttons.

For example here:

The two left cubes are subdivided and bevelled, one of them with ‘Set Smooth’

The right cubes are metacubes converted to mesh, with the rightmost one using ‘Set Solid’.

F9, Links and Materials tab, just toggle between ‘Set Solid’ and ‘Set Smooth’ after converting.