This method is commonly used now days as it is efficient than the two wire control system. It should also help in understanding the functions of each type of switch.

Two Way Light Switching Explained Youtube
Two way light switch wiring diagram new zealand. When wiring a 2 way switch circuit all youre really doing is controlling the power flow switching offon to the load a light lamp outlet ceiling fan etc now a typical circuit will contain a 3 wire cable known as romex. This arrangement is often found in stairways with one switch upstairs and one switch downstairs or in long hallways with a switch at either end. This is the new method to make a 2 way switching connection as it is slightly different from the two wire control method. How to connect 2 way switch wiring using three wire control. We have a light at the top of some stairs. Red black green or brown blue green yellow cable feeds the switch.
Basically connecting a switch either end of a room to control the same lights. One of these for two way operation of the light switch. There is a single switch at the bottom of the stairs and at the top of the stairs there are a set of 4 switches. How to wire a 2 way switch circuit. 2 way switching means having two or more switches in different locations to control one lampthey are wired so that operation of either switch will control the light. All you need to know about wiring the 2 way switch.
A two or three core cable. When the switch at the bottom of the stairs is off we cannot use the switch at the top of the stairs to turn on the light. The cable consist of a black wire a. Where 0 represents the off condition and 1 represents the on condition. Two way switching made easy. The third conductor green or green yellow is only needed if the lamp requires a safety earth black neutral blue wire goes to the loop terminal a red positive brown wire goes to one switch terminal and another from the other side of the switch to the lamp.