Every concept, animated
Short animated explainers for 795+ concepts across 12 subjects. Watch, learn, and explore — all free, forever.
A* Pathfinding · Shortest Route
A* pathfinding explained in 3D — watch the algorithm explore cells using f = g + h to find the shortest path through obstacles. Interactive animation on Unseel.
Computer ScienceB-Tree
Each node holds many sorted keys — dozens to hundreds — keeping tree depth shallow enough that million-record lookups fit in 3-4 disk reads. The backbone of every database index.
Data StructuresBellman-Ford
V-1 rounds of edge relaxation find shortest paths from a source — even with negative weights. Slower than Dijkstra, but strictly more general. Detects negative cycles too.
AlgorithmsBig O Notation
How Big O notation measures algorithm efficiency — see O(1), O(log n), O(n), O(n²), and O(2ⁿ) growth rates compared in 3D.
AlgorithmsBayes\' Theorem
Update beliefs when new evidence arrives. A positive medical test on a rare disease gives a surprisingly low probability of actual disease — Bayes corrects the intuition.
ProbabilityCentral Limit Theorem
Averages of any distribution converge to a normal distribution as sample size grows. Why the bell curve appears everywhere — and statistics can work at all.
StatisticsChain Rule
When functions are nested, the derivative is the product of outer and inner derivatives. The foundation of backpropagation in neural networks.
CalculusCompleting the Square
A geometric trick turning any quadratic into a perfect square plus a constant. Derives the quadratic formula and powers conic-section analysis. From Babylonian tablets to modern algebra.
Algebra