This node is used in the Calculation Module.
It's the final output node of any calculation - the number that is sent to this node is delivered to the user.
Input #1 is a number and is the final value of the calculation.
The title of this node is also the title of the value in the final calculation. If you call this node Total Weight, the final calculation will have a column named Total Weight.
You can have a single calculation with multiple different outputs, as long as they all have unique titles.