A B-tree of order m (the maximum number of children for each node) is a tree which satisfies the following properties :

1. Every node has <= m children.

2. Every node (except root and leaves) has >= m/2 children.

3. The root has at least 2 children.

4. All leaves appear in the same level, and carry no information.

5. A non-leaf node with k children contains k – 1 keys