B-tree

noun1

1. •
   An indexed data structure suitable for storage of a large number of items in a balanced fashion, with very few disk accesses required for locating the correct record block.

noun1

1. •
   An m-ary tree data structure with a variable but often large number of children per node. It can be viewed as a B-tree in which each node contains only keys (not key–value pairs), and to which an additional level is added at the bottom with linked leaves.