Skywind: Playing the plot of Morrowind in the Skyrim engine. Game mechanics, spells, skills, models, textures, and bugs are all going to be similar to what you have in Skyrim, give or take some modding.

OpenMW: Playing Morrowind in an open source, crossplatform game engine. You are playing the exact same game as TES III (gameplay mechanics, spells, models, textures, etc are 1:1 identical in a vanilla install) but the code behind it is less buggy, more moddable, and it provides many modern quality-of-life improvements that the original engine couldn't do.

They are both in some way related to The Elder Scrolls III: Morrowind
OpenMW is an open source game engine that can be used to play Morrowind. (There is an unfinished "Example Suite", a CC0 licensed game data that can be used instead of Morrowind game data, so technically OpenMW does not play just Morrowind. Feel free to come help finish the Example Suite)
Skywind is remake / reimagining of Morrowind game in a modified Skyrim engine.

tl:dr it's not