TreeView is the Parent Child relationship which is used for to show computer data in Parents and Child nodes with the help of + Symbols and it is also known as data view technique. The TreeView control contains hierarchy of TreeView Items controls which are used to display information in a hierarchical structure by using collapsible nodes . There have one root node which is called starter node or parent node that can be expanded when there left child nodes.You can explicitly define the TreeView content. The user can expand the TreeNode by clicking the plus sign (+) button, if one is displayed next to the TreeNode, or you can expand the TreeNode by calling the TreeNode.Expand method.