The whole tree and each node can be expanded or collapsed. When a node is collapsed, all the nodes that would normally appear below it are hidden. When a node is expanded, all the nodes below it are shown. By selectively expanding or collapsing nodes, you can view exactly the amount of detail you need to understand and manipulate the data.
All the nodes in the whole tree can be expanded or collapsed by clicking on the Expand and Collapse icons on the tool bar. Individual nodes can be expanded or contracted by moving the mouse cursor to the icon for the node and double clicking the left button. If the node is collapsed, it will expand. If the node is expanded, it will contract. You can also expand or collapse a node using the arrow keys to highlight the node and then hitting the Enter Key.