A contact is a place for a wire to originate or terminate. You may wire CAMs and / or chips together by attaching wires to their respective contacts. When you move the mouse over a contact, the cursor will change to the wiring cursor. Click with the left mouse button to attach a wire, drag the wire to the other contact you want to be connected, then release the left mouse button to make the connection.
You may also attach signal generators and / or oscilloscope probes to valid contacts for simulation use. Click with the right mouse button on a contact to get a popup menu with the option to attach signal generators or oscilloscope probes.