M-ary tree

In graph theory, an m-ary tree (for nonnegative integers m) (also known as n-ary, k-ary, k-way or generic tree) is an arborescence (or, for some authors, an ordered tree) in which each node has no more than m children. A binary tree is an important case where m = 2; similarly, a ternary tree is one where m = 3.