Define a B tree of order m.
B Tree of order m
A balanced multiway search tree of order m in which every non root node having at least m/2 keys is known as a B-Tree of order m. where order means maximum number of sub-trees.
A B-Tree of order m is either the empty tree or it is an m-way search tree T with the following properties:
(i) The root of T has at least two subtrees and at most m subtrees.
(ii) All internal nodes of T (other than its root) have among [m / 2] and m subtrees.
(iii)All external nodes of T are at the similar level.