When we uses B-Tree. Each data object has a key, all the key who are less than the given are placed on left side where as key who are greater than the given key are placed on the right side. Using this method key maintain a tree like structure for the given list of item.Some, Important terms that we generally used in B-Tree are given below: Node: Indicates the data items 0f the list in B-Tree. Root node: Indicates the first node in B-Tree. Left side: Which data items on the left side and less than the current item. Right side: Which data items on the Right side and greater than the current item. balance: This is use to check the tree is balance or not.