The thesis option is most appropriate for those who are interested in pursuing a doctoral degree or a research-related profession following their M.S. The thesis option requires that you complete an independent research project under the guidance of your advisor and your committee. This thesis project is typically conducted during the 2nd year of your program.
The coursework only option (i.e., non-thesis) is most appropriate for those who are interested in obtaining an advanced degree but who do not intend to go on to doctoral studies. Most students who obtain an M.S. degree non-thesis use this to enhance their position within their chosen career path.