What is a difference between spa therapy and massage therapy?

Spa therapy can refer to a water treatment, as in a hot tub or spa. Or it can refer to any number of wellness treatments available at a spa.
Massage therapy is one of those treatments. There are many types of massage therapy, but all involve rubbing and manipulating the muscles to reduce tension.

hi , I am Julia Rhodes of West London Colonics.( WLC )
As other respondents to your question have indicated, SPA therapy is kind of like an umbrella category that scan house number of individual therapies, many have a water component.
I am responding to this question on 2 counts;
(1) colon hydrotherapy is often offered as a spa treatment; at WLC we offer it as a specialist treatment as we are a bespoke, specialist clinic
(2) colon hydrotherapy also incorporates as a adjunct element abdominal massage, which is often a well regarded , well appreciated part of the treatment.
Within these web pages its sometimes referred to as colonic treatment.

Spa treatment includes massage therapy like as thai massage, hot stone massage, sport massage, deep tissue massage and there are various massage techniques.

Spa therapy - water treatment, as in a hot tub or spa. Or it can refer to any number of wellness treatments available at a spa.
Massage therapy is one of those treatments. There are many types of massage therapy, but all involve rubbing and manipulating the muscles to reduce tension. Swedish massage is the most common, or "classic" massage therapy, but Shiatsu, hot stone, and Thai massage are other common types.
Other kinds of treatments available at a spa include "holistic" treatments, such as Ayurvedic treatments and yoga style classes, that address both the body and the mind or emotions Most are based in Eastern medical and spiritual philosophies.