Summary: The website 3Blue1Brown offers animated math lessons on a variety of topics, including calculus, linear algebra, neural networks, geometry, analysis, topology, group theory, computer science, physics, probability, epidemics, and lockdown math. The lessons are available in written form and cover a range of difficulty levels. The website is supported by contributing members who receive benefits such as early access to new videos and having their names in the video credits. The lessons are free from brand integrations and sponsor messages, and there are no paywalls.