At least in my experience, an MSc is constituted by "tackle one interesting idea/problem, under supervision and guidance from your advisor". The exact degree of peonage or independence you are given varies with how the advisor and student get along, and with their goals. However, generally, MSc research constitutes one paper's worth of output (two if you're good, or sometimes even quite commonly nowadays, since two papers' worth means more labor got done for the same "price" in stipends and degrees), and is more closely supervised and less independent than a PhD (but still more independent than a BSc thesis).
On the other hand, my experiences have been weird, in that I had near-total independence for my BSc thesis (which, as a result, simply was not very good even though it was accepted with honors) (because my undergrad thesis advisors were involved in administration and I was doing a topic politically disfavored in that department), and an uneven degree of supervision for my MSc research (I've had a lot of guidance on what experiment to do and what statistics to run, but my advisor has never told me how to find the previous literature on our subject, even when I ask).
On the other hand, my experiences have been weird, in that I had near-total independence for my BSc thesis (which, as a result, simply was not very good even though it was accepted with honors) (because my undergrad thesis advisors were involved in administration and I was doing a topic politically disfavored in that department), and an uneven degree of supervision for my MSc research (I've had a lot of guidance on what experiment to do and what statistics to run, but my advisor has never told me how to find the previous literature on our subject, even when I ask).