What does "Orwellian" mean?

A youtuber I recently started following, "Fandom Musings," just posted this video, which  explicates what "Orwellian" means, and what things about the current administration are Orwellian (and some things that aren't, but are awful for other reasons).

She covers the key points that I think everyone needs to understand about that book and this administration: that language is fundamental to thought. That the Trump administration is dismantling language, controlling information, teaching and practicing doublethink.

And she points out that this is not yet the world of 1984, and that we need to work very hard right now to keep it that way.