B+ Tree is a type of tree, which represents sorted data in a way that allows for efficient insertion, retrieval and removal of records, each of which is identified by a key.

It is a dynamic, multilevel index, with maximum and minimum bounds on the number of keys in each index segment (usually called a 'block' or 'node').

In a B+ tree, in contrast to a B-tree, all records are stored at the lowest level of the tree; only keys are stored in interior blocks.

Two search methods available in the btree implementation:

First method is performed in the typical manner, starting at the root, the tree is traversed top to bottom, choosing the child pointer whose separation values are on either side of the value that is being searched.
Second method is more sophisticated and flexible.

Different parameters of search can be set up by user, including starting point and method which will test each next new value. For example, using this type of search user can make efficient wildcard search on a string based btree, by simply writing wildcard test function and performing search in the btree.