What are the differences between these levels of study?
A Phd is a three or four year degree awarded following research and a thesis.
A Masters course is a taught postgraduate degree usually of one or two years duration.
A Masters thesis is a research degree of one or two years duration awarded following research and a thesis.
A Post-Graduate Diploma is usually two-thirds of a taught masters and is awarded to someone who did the examination component but did not complete a dissertation.
A Post-graduate Certificate is usually one-third of a taught masters and is awarded to someone who left after completing half of the course credits.


These terms would be used in areas based on the British University system, but all have analogues in the Bologna Process.