There may be no difference. Check it out!
For over 30 years, Mindfulness Based Stress Reduction (MBSR) has been the gold standard of teaching mindfulness in a secular setting for the relief of
physical and psychological suffering. It is taught by people who have committed themselves to training, doing retreats and having a personal practice
themselves, over many years.
However, many people are now offering “mindfulness” courses “based on MBSR” or “based on the work of Jon Kabat-Zinn” with very little personal experience
and immersion in mindfulness practice themselves, and little or no training in MBSR. These courses are often shorter, perhaps 6 sessions of 1.5 hours
(ie 9 hours long) or 6 sessions x 2 hours (12 hours long) for around $400. This works out as more expensive than the MBSR program which is 27 hours
long, including a silent retreat day, plus email and phone contact with the teacher if you need it during the 8 weeks.
You might like to ask the teacher of these courses if they have specific training in teaching mindfulness, have completed retreats and if they adhere to
the Good Practice guidelines.