What is a common use for a 3-way switch?

A 3-way switch is commonly used in residential lighting to control a single light fixture from two different locations. This setup is particularly useful in scenarios where you may want to turn a light on or off from both ends of a hallway or at the top and bottom of a staircase, for instance.

To achieve this, 3-way switches are wired together in such a way that changes made at one switch affect the state of the light fixture, allowing for convenient control and enhancing the functionality of the lighting system. This capability of controlling one light from two different points illustrates the versatility and practical application of 3-way switches in home wiring configurations.