Introducing the non-linear tree data structure, including binary trees, traversals, and key properties.
Defining the structure of a binary tree and its basic terminology (root, leaf, parent, child).
Implementing the three fundamental depth-first traversal methods for binary trees.
Implementing breadth-first or level-order traversal using a queue.
Calculating key properties of a binary tree like its height and diameter.
Converting a binary tree to a string (serialize) and back (deserialize).