What are the different types of tree traversal?

Tree traversals visit all nodes systematically: In-order (left, root, right) gives sorted order for BST, Pre-order (root, left, right) is used for creating tree copies, Post-order (left, right, root) is used for deleting trees, and Level-order (breadth-first) visits nodes level by level using a queue. The first three are depth-first traversals using recursion or stack, while level-order uses a queue.