The answer is definitely to use multiple view modes. View modes are different configurations of field displays per bundle. D7 comes with "default" and "teaser" but you can add more via hook_entity_info_alter() or by using Display Suite to do this through an easy interface.
The next question is how to actually show the user the 2nd view mode – on node/123/view it's going to use 'default'. You can use a different view mode by using Views and selecting the alternative view mode on the node display settings, or you could load the node programmatically and set the view mode there:
$node = node_load(123);
$node_view = node_view($node, 'my_custom_view_mode');