Nodal force

Hi,

What is the difference between the nodal force (NFORC) and Reaction force in abaqus. I applied some displacement in my model, when checking the Reaction and Nodal force at the same node, Nodal force is just half the reaction force. Then I did some experiment and applied some load on a node, after solution when i check the nodal force on the same node, it is half of the applied load. Why is it not  same as the load I applied? I am confused. Please help me.

 Thanks,

Anshul