SSC: Secondary School Certificate. This is provided by Indian states. Suppose, if you are studying in Andhrapradesh, you have syllabus decided by state government (not government exactly, but a committee appointed by them). They conduct exams and give results.
CBSE: Central Board of Secondary Education. This is of total India, same syllabus. Throughout India, at same time, exams will be held.
ICSE: Indian Certificate of Secondary Education. This is international standard with Indian flavour. This is started by Cambridge University. Schools who like can be affiliated to it and can have its syllabus in their schools.This exams are going to be held in feb,2011.
IGCSE- International General Certificate of Secondary Education. This gives international recognition to you of your studies.This is under Cambridge university. It will have a scope of subjects like Languages, Humanities,Vocational etc.
IB: The International Baccalaureate.It is with the theme of "Quality education for a better world",offers programmes of international education to help develop the intellectual, emotional and social skills to live, learn and work in a rapidly globalizing world.