andreaellamaria

To summarise: you take 6 subjects (from the different sections) for 2 years, write an Extended Essay, do 150 hours of CAS and sit through TOK lessons enough to do your presentation/write your TOK essay. Throughout this time you do pieces of coursework for different subjects. Then you are examined in all 6 subjects over the course of 2 weeks at the end of your course; for the N. hemisphere this is in May, for the S. hemisphere this is in November.

Some schools split it up to make it easier and you are examined in some subjects in year 1 and some in year 2.

Certificates mean you're not taking the full diploma -- you don't have to do 6 subjects, don't have to do subjects from each of the 'areas', don't have to do CAS, don't have to do an EE and don't have to do TOK. On the other hand, many Universities ask for the diploma as part of their minimum requirements, so few people do certificates and it's common to do the diploma. To pass the diploma there are a series of requirements including not failing TOK/EE, doing CAS and getting a minimum mark of 24 with a minimum of 12 points split between your HL subjects. There are some other requirements, but most people worry most about those two!

Each subject is graded out of 7 to generate these points, so 6 x 7 means a maximum of 42 points from your subjects. The maximum score is 45 -- this is achieved by adding on 3 bonus points which come from completion of TOK/EE to different levels. If you do well in both, you get 3 points, if you do badly in one but well in the other, 2 points, and badly in both is 1 point aaaand it's slightly more complicated but you get the picture. No points are awarded for CAS, it's just considered a minimum requirement which you either meet or fail to meet.

Hope that roughly answers your question.