Postgraduate certificate requires 3 - 6 months full time study. PG certificate is awarded after the end of first semester of taught Masters or for specialised short term courses. These are very intensive in nature and most of them offer thorough grinding on fundamentals. These are suitable for working professionals. The difference between these two lies in the nature of work undertaken, period of study and method of examinations.
Taught courses involve formal lectures, seminar programmes and written examinations.
They impart advanced knowledge in the subjects that are previously studied at the undergraduate level more generally. Taught courses provide an opportunity to enhance the knowledge in the subject previously studied or to study a new subject. PG courses in the UK are very intensive. They can be completed in an academic year whereas in other parts of the world it takes two years. You may heard that Postgraduate work is a lonely experience.