It is true that there are several wiring configurations for wiring 3 way light switches and all of the wiring configurations will depend on where the incoming circuit power is located and once that is identified the rest of the three way wiring connections are straight forward. The black and red wires between sw1 and sw2 are connected to the traveler terminals.

Multiway Switching Wikipedia
Three way lighting circuit diagram. Switches are shown as dotted rectangles. The 3 way lighting circuit which is often referred to as the two way and intermediate lighting circuit is a common arrangement usually found in large houses. 3 way switch 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. In this diagram the electrical source is at the first switch and the light is located at the end of the circuit. L and n indicate the supply.
Three way switching old cable colours. The first step in any electrical project is to make sure there is no power going to the circuit you plan to be working on. Three way switching old cable colours. Take a closer look at a 3 way switch wiring diagram. Three wire cable runs between the switches and 2 wire cable runs to the light. Wiring diagram 3 way switch with light at the end.
This might seem intimidating but it does not have to be. This allows a single light to be turned on or off from any of the switchesthis page shows it wired in the new cable colours if your house has the old colours you want to go here. 3 way switch diagrams for multiple light fixtures. These diagrams show various methods of one two and multiple way switching. With a pair of 3 way switches either can make or break the connection that completes the circuit to the light. Turn the power off at circuit breaker.
With these diagrams below it will take the guess work out of wiring. The most basic circuit with only two wires at the switch. This allows a single light to be turned on or off from any of the switchesthis page shows it wired in the new cable colours if your house has the old colours you want to go here. A three way switch is fundamentally different in its operation from a regular two way switch. Earth wires are not shown. Two way switching 2 wires.
You must completely forget about the notion of a switch being a simple openclosed circuit and look at the diagram of the circuitry of this modern alternative. Knowing how to wire a three way lighting switch comes down to understanding the operation of this contraption. Wiring a 3 way light switch. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. Here we have a 3 way switching lighting circuit sometimes called two way switching with intermediate. If you are familiar with wiring a two way lighting circuit then the addition of an extra switching point will not be much of a problem.
Basic 3 way switch diagram how to wire 3 way light switch step by step. Here we have a 3 way switching lighting circuit sometimes called two way switching with intermediate.