A neck massager is a device designed to provide relief from neck pain and tension. The technology used in neck massagers has evolved over time, with the most advanced models using a combination of massage techniques, heat, and vibration to provide relief. 

The most common massage techniques used in neck massagers are kneading, rolling, and percussion. Kneading is a technique that involves manipulating the muscles in the neck with a circular, pressing motion. Rolling is a technique that uses a rolling motion to massage the muscles in the neck. Percussion is a technique that uses a tapping motion to stimulate the muscles in the neck. 

Heat is also used in neck massagers to provide relief from muscle tension. Heat can be applied through a variety of methods, such as infrared light, heated water, and electric heating pads. Heat helps to relax the muscles in the neck, which can reduce pain and tension. 

Vibration is another technology used in neck massagers. Vibration helps to stimulate the muscles in the neck, which can help to reduce pain and tension. Vibration can be applied through a variety of methods, such as vibrating plates, vibrating balls, and vibrating rollers. 

Neck massagers are a great way to provide relief from neck pain and tension. The combination of massage techniques, heat, and vibration can help to reduce pain and tension, and can help to improve overall neck health.