Each disc is a node and its number is the value. Smaller values hang to the left, larger to the right, so reading the discs from left to right gives the sorted order.

The badge is the balance factor: the height of the left subtree minus the height of the right. Each arm tilts toward the taller side.

Cobalt is the value being inserted, searched or deleted, and the wires it has followed. When a node reaches ±2, the tree rotates: the link between two nodes turns about its middle like a see-saw, and the red disc drops back into balance.