This visualization demonstrates how valid ranges change during Binary Search Tree (BST) traversal. The ranges help ensure that each node maintains the BST property: all values in the left subtree are less than the node's value, and all values in the right subtree are greater than the node's value.
In a BST, each node has a valid range of values it can hold. We start with the range [−∞, +∞] for the root node. As we traverse down the tree, these ranges narrow based on the BST property.