Full-body massages are not a particular kind of a massage but rather an umbrella term for various massages. All these massages have in common that they include all body parts (besides private parts). Next to full-body massages, there are also partial body massages focussing on one specific body area like back, neck, shoulders, feed or face.
There are various reasons to enjoy a full-body massage. Sometimes pain in certain body regions might be the cause or chronic diseases. Of course the desire for relaxation is also a valid reason! Once muscles are loosened people often start also to mentally relax. According to the holistic approach body, mind and soul are connected with each other and therefore also influence one another.