My Masters Degree consisted of a formal programme of study plus the initial stages of a research project. The latter of which had to be written up as a thesis. The Masters Degree lasted 1 year, after which I took an examination, and passed, but the thesis was also assessed as part of the successful attainment of the Masters degree. The next 2 years were my PhD phase,and were purely an extension of the research project that I started during my Masters. The PhD phase was judged purely on the originality of the research work and the thesis that described that work.
For certain BSc+BSc does not = MSc, and MSc+MSc does not = PhD!.
Although I believe at Oxbridge BA+cash= MA