Manim: Animation engine for explanatory math videos
If you haven't heard of 3 Blue 1 Brown, congrats[0] because you are in for a treat. He is simply one of the best intuitive math video creators in the game right now. I can't even a good intro, just find something interesting or something you're confused about and enjoy[1][0]: https://xkcd.com/1053/
[1]: https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw