Defination of Some Data Structure

Binary Search tree is a binary tree in which each internal node x stores an element such that the element stored in the left subtree of x are less than or equal to x and elements stored in the right subtree of x are greater than or equal to x. This is called binary-search-tree property.

An AVL tree is a binary tree in which the difference between the height of the right and left subtrees (or the root node) is never more than one.

A hash table is made up of two parts: an array (the actual table where the data to be searched is stored) and a mapping function, known as a hash function. The hash function is a mapping from the input space to the integer space that defines the indices of the array. In other words, the hash function provides a way for assigning numbers to the input data such that the data can then be stored at the array index corresponding to the assigned number.

Heap Trees (or just Heaps) are a form of binary tree in which each node is greater than or equal to both of its children. Thus, the largest element in the entire tree is always the root of the tree.