Level order traversal of a rooted tree can be done by starting from the root…

Answer: breadth-first search (BFS) — level order traversal visits nodes one level at a time.

Implementation (standard approach):

• Initialize an empty queue and enqueue the root node.

• While the queue is not empty:

  • Dequeue a node and visit it.

  • Enqueue the node's children (for a binary tree, enqueue left then right if they exist).

• Continue until the queue is empty; nodes are visited level by level.

Why the other traversals are not level order:

• Preorder: a depth-first order (visit node before children), so it does not visit all nodes at one level before descending.

• Inorder: a depth-first left-root-right order (for binary trees), not level by level.

• Depth-first search (DFS): explores along branches before backtracking, unlike BFS which explores by levels.