An MSc is a university degree in a science subject that you take after your first degree (the bachelor's). The letters stand for Master of Science. You study more deeply — often one or two years in Britain — and usually finish with a paper or a project. It is a formal, letters-after-your-name word: you write it on a CV. In speech, British people say 'an MSc' or 'a master's in chemistry'. Though actually, not every science master's is written MSc: some countries write MS, and a few old universities still give an MA even for science, because of history, not because the course is 'arts'. In Taiwan, people often just say they are doing a 碩士 and only say MSc when the course is British-style. It is not a first degree, and it is not a PhD; the PhD comes later if you keep going.