B-Tree
Rudolf Bayer & Edward M. McCreight, 1972
O(log n)B-trees generalize binary search trees so each node stores up to 2t−1 keys (here t = 2) and routes through up to 2t children, keeping height logarithmic in the number of keys. Splits propagate upward when a node overflows. The visualization highlights the insertion path in gold and marks splitting activity with a coral outline.