How to share the same value among more than one input port
If you have several input ports in your composition that all need to stay in sync with the same data, then it’s usually a good idea to feed cables to all of them from a single output port. But what if the data isn’t coming from an output port — what if it’s a constant value? In that case, you can use a Share Value node to set the constant value in one place and propagate it from the Share Value node’s output port to all connected input ports.
Here’s an example that draws two shapes, all of the same height. You could accomplish the same thing without the Share Value node by using input editors to individually set the Height input ports to 0.8. The advantage of using Share Value is that, if you change your mind and decide the height should be 1.0 instead, you only have to edit it on the Share Value node’s input port instead of on all connected input ports.