Teleport vs Flight

What are the differences between the Flight and Teleport types of unit movement?

In Heroes of Might and Magic III, there are three types of unit movement: ground, air, and teleportation. The last of these types is possessed by only one type of unit - Devils - and is treated as something special and significant, being labeled as a unique type and even having its own mouse icon. However, as far as I can tell, teleportation does not appear to have any differences to flight.

Both flight and teleportation appear to avoid all obstacles in their way, including terrain doodads, magical spells, and other creatures. Teleport also still has a range limited by the unit's speed, just as with the other two movement types, preventing Devils from being able to teleport across the entire battlefield without limit.

It seems to me that flight and teleportation have no functional differences. Is this true? If not, how do they differ? If so, did the developers decide to give it special treatment simply for aesthetic appeal?

As far as gameplay mechanics go, there is no difference between them. Even this wiki categorizes Devils as flyers.

Also, I have just found an image that shows the standard flight movement icon for Arch Devils too.