The black and red wires between sw1 and sw2 are connected to the traveler terminals. This is only a wiring schematic and not the actual wiring method used for 3 way switch installations.

Lighting Circuit Diagrams For 1 2 And 3 Way Switching
3 way switch schematic wiring diagram. The diagram below is based on the video you watched above. Take a closer look at a 3 way switch wiring diagram. A 3 way switch wiring diagram is a simple drawing showing how to connect the wires to each of the four screws on the 3 way switch. In this diagram the electrical source is at the first switch and the light is located at the end of the circuit. Three wire cable runs between the switches and 2 wire cable runs to the light. The black screw on a 3 way switch diagram is for the continuous hot wire that comes from the circuit.
Wiring diagram 3 way switch with light at the end. Two very old three way switches. 3 way switch schematic wiring diagram. Wiring a 3 way light switch is certainly more complicated than that of the more common single pole switch but you can figure it out if you follow our 3 way switch wiring diagram. With a pair of 3 way switches either can make or break the connection that completes the circuit to the light. What is the black screw for on a 3 way switch diagram.
Wiring a 3 way light switch. See alternate 3 way switch wiring configuration for another way 3 way switches may be wired. This might seem intimidating but it does not have to be. If you have any problems with these switches it may be best to call an electrician. Below is a simple 3 way schematic that can be applied to all three way electrical light switch connections. With these diagrams below it will take the guess work out of wiring.
Unfortunately not all 3 way switches are wired the conventional way. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. The diagrams below show the conventional wiring for 3 way switches. 3 way switch wiring diagram. Two very old three way switches are depicted in the photo above.