Explanation with Wiring Diagram
Four-way switches are switches that are used to control lighting. This particular switch is going to control the lighting from three or more locations.
This type of switch is going to have four different terminals. Each terminal is going to have two pairs of travelers that accompany it; one set is generally going to be black while the other brass.
Four-Way Switch Wiring
Using too high of a voltage for your space will cause a lag in your appliances and lighting.
Why Use 208v Instead Of 240v?
Three-way switches primarily differ from four-way switches in that they have three terminals instead of four. These are going to control a light from two or three switch locations.
What Is The Difference?
Four-way switches are the same concept, except that they have four terminals with two sets of travelers that will go between two 3-way switches or a 3-way switch and another 4-way switch.
Switch Types Based On Light Switch Count