"There are over 80 different modalities of massage therapy. Some therapists specialize on specific ones, others use a blend of several in one session depending on what the client needs."
A massage modality is a type or style of massage that has a specific technique and achieves a specific goal. Some modalities are taught to and used by just about every massage therapist that learns how to do massage, some are very specialized and can take years to master. Some modalities are familiar such as Swedish Massage, Deep Tissue, and more. Others can be more specialized such as Pregnancy Massage, Oncology Massage, Sports Massage, etc. Even with specialty modalities, many forms of other massage can be incorporated. For example, a pregnancy massage incorporates elements of Swedish massage, and Lymphatic Drainage, among others. Swedish Massage itself is usually referred to as the "standard, regular" type of massage, but even that has various parts and aspects to it that can change as needed.
The point of different modalities is to get the best results for what needs to be accomplished. If someone wants to simply relax and zone out, lighter pressure, and techniques with smooth, long strokes are more likely to be used that rough percussion and intense stretching. Likewise, if someone comes in for an injury or to relieve a chronic issue, the massage may start out with one type of modality, but as the therapist gets in there, and identifies the issue and how it is responding, different techniques may need to be used to achieve the desired results. Massage is in no way "one size fits all". Everybody comes for a massage for different reasons, and has different needs and preferences, so the massage needs to be just as varied and flexible.