Data flows along connections from the output ports on the right side of nodes to input ports on the left side of other nodes. You can connect the same output to as many inputs as you want.
Do either of the following:
After the first click, you can pan (middle-mouse button, or Alt+middle-mouse button) and zoom (scroll wheel, or Alt+right-mouse button) the graph if necessary..
For nodes that support new ports, you can also click the New Port icon (gray +) to create a port.
Instead of clicking twice, you can click on port, drag to another port, and then release the mouse button. However, you cannot pan with this method.
You can also break multiple connections by pressing Alt+Shift and dragging across them.
Alternatively, click and drag to select one or more connections, and then press Delete or Backspace.