Both are excellent opportunities for relaxation and distressing. The main difference is the approach and the aim of the massage experience.
The aim is to relax as well as arouse the physical body. The masseuse can involve herself as much as she feels comfortable in satisfying the client's needs. The massage is often described as an exciting, arousing, sensual experience. Alternatively described as a long tease before the "Happy Ending"... As long as both parties are in agreement, mutual touch can be allowed.
The authentic Tantric massage focuses on the spiritual aspect of Tantra. The client is encouraged to connect with himself on a deeper level and is taught how to control and manipulate his sexual energy by practising basic control techniques. The client's awareness increases gradually over time thus giving him greater sexual control. The therapist projects her sexual energy into the energetic body of the client on a subtle deeper level of the subconscious mind. The masseuse is not there for her own sexual needs, she is there to facilitate the flow of sexual energy in a harmonious way. It's often described as an uplifting and elevated experience.