link :

https://slidetodoc.com/full-and-complete-binary-trees-binary-tree-theorems/

Full and Complete Binary Trees Binary Tree Theorems 1 Here are two important types of binary trees. Note that the definitions, while similar, are logically independent. Definition: a binary tree T is full if each node is either a leaf or possesses exactly two child nodes. Definition: a binary tree T with n levels is complete if all levels except possibly the last are completely full, and the last level has all its nodes to the left side. Full but not complete. Neither complete nor full. Complete but not full. Full and complete. CS@VT Data Structures & Algorithms © 2000 -2020 WD Mc. Quain