There are fives ways to view nodes within the Node Editor: simple, connected, full, view all attributes, or custom attribute view. See Node Editor view modes for more information on the view modes.
This topic is applicable to both the Node Editor and the Hypershade.
Changing the view mode for individual nodes
You can change the view mode for each node by clicking the 
(simple), 
(connected), 
(full), or 
(custom) icons on the top right corner of each node. Click 4 to view all attributes if you do not have a custom attribute view saved.
If a node has a corresponding custom attribute view saved, hotkey 4 displays it in its custom view. If a node does not have a corresponding custom attribute view saved, hotkey 4 displays all its attributes.
See Customizing the list of node attributes for more information on how to create a custom attribute view.
Changing the view mode for selected nodes
Simple, Connected, Full modes: Select the nodes for which you want to change the view mode and click the , , or icons on the Node Editor toolbar. Alternatively, you can use the 1, 2, 3 hotkeys to switch between these three view modes. You can also select the Edit > Simple Mode, Edit > Connected Mode, or Edit > Full Mode options from the Node Editor menu bar. See Node Editor menu bar for more information.
Custom mode: You can customize the list of attributes displayed for each node. To create a custom list of attributes, 
-click the node and select Edit Custom Attribute List. After creating your custom attribute lists, click or hotkey 4 to display the selected nodes in their corresponding custom attribute views. You can also select Edit > Custom Mode from the Node Editor menu bar. See Customizing the list of node attributes for more information on how to customize the list of attributes displayed for each node.
View all attributes: If there are nodes among the selection that do not have a corresponding custom attribute list, clicking (or selecting Edit > Custom Mode or pressing hotkey 4) displays them in full mode. Regardless of which workflow you use (hotkey, icon, or menu item), nodes that have a corresponding custom attribute list display with a on the top right corner, while nodes that do not have a corresponding custom attribute list display with a on the top right corner.
Changing the view mode for all nodes
When none of the nodes are highlighted (active) in the Node Editor, clicking the icons in the toolbar, or selecting the same options from the Node Editor Edit menu, or using the Edit menu shortcuts, affects all nodes.
You can also customize this option in the Preferences window, and your nodes are displayed in the view mode you selected the next time you create a Node Editor window. See Node Editor Preferences for more information.