http://stackoverflow.com/questions/870218/differences-between-b-trees-and-b-trees

B树与B+树.png

1. In a B tree search keys and data stored in internal or leaf nodes. But in B+-tree data store only leaf nodes.

2. Searching any data in a B+ tree is very easy because all data are found in leaf nodes.
3. In a B tree, data cannot be found in leaf nodes.
4. In a B tree, data may be found in leaf nodes or internal nodes. Deletion of internal nodes is very complicated. In a B+ tree, data is only found in leaf nodes. Deletion of leaf nodes is easy.
5. Insertion in B tree is more complicated than B+ tree.
   B+ trees store redundant search key but B tree has no redundant value.
6. In a B+ tree, leaf nodes data are ordered as a sequential linked list but in B tree the leaf node cannot be stored using a linked list. Many database systems' implementations prefer the structural simplicity of a B+ tree.

http://www.cnblogs.com/ivictor/p/5849061.html