Hook_load = Hook_node_load

Hook_node_load can be used everywhere, after node is taken out of the database and then modifies the value of $node.
There are two cases of hook_load

   DPM (Node_type_get_base (' Poll ')); Poll Poll_load would be loaded   DPM (Node_type_get_base (' article '));//node_content

So

Node_load (' poll ' s ID '); node_load (' normal node ' id ');

The first one will excite the poll_load, and in poll.module it is not visible that the direct call Poll_load is called by the Attachload method of the Nodecontroller.
The second, because it is a node type defined by UserInterface, cannot activate Hook_load, but activates Hook_node_load ()

Hook_load = Hook_node_load