What are...operads?

Описание: Goal.
I would like to tell you a bit about my favorite theorems, ideas or concepts in mathematics and why I like them so much.

This time.
What are...operads? Or: Topological algebra.

Disclaimer.
Nobody is perfect, and I might have said something silly. If there is any doubt, then please check the references.

Slides.
http://www.dtubbenhauer.com/youtube.html

Thumbnail.
https://static01.nyt.com/images/2012/...

Basis of this video is this awesome blog.
https://www.math3ma.com/blog/what-is-...
https://www.math3ma.com/blog/what-is-...

Operads.
https://www.ams.org/notices/200406/wh...
https://arxiv.org/abs/math/0305049
https://en.wikipedia.org/wiki/Operad
https://ncatlab.org/nlab/show/operad
https://bartoszmilewski.com/2015/10/0...

The phylogenetic tree.
https://arxiv.org/abs/1512.03337
https://johncarlosbaez.wordpress.com/...
https://golem.ph.utexas.edu/category/...

A variation (planar algebra).
https://arxiv.org/abs/math/9909027
https://en.wikipedia.org/wiki/Planar_...

Mathematica.
https://mathworld.wolfram.com/Operad....

Pictures used.
Many pictures from https://www.math3ma.com/blog/what-is-...
Picture from https://www.ams.org/notices/200406/wh...
https://en.wikipedia.org/wiki/Planar_...
https://math.ucr.edu/home/baez/ecolog...
Picture from https://johncarlosbaez.wordpress.com/...

YouTube and co.
   • Operads (Bruno Valette)  
   • Operads