in the UK, the GCSE can only be taken through a school / colleage environmet, normally for students less than 18years of age. If you are older that 18 then you can only take the IGSCE. The GCSE courses, in general, have associated assignments which are graded, but the IGSCE does not, its purely exam based. Also within GSCE there are two levels foundation french and intermediate, if you seek an A then you need to enter the intermediate GCSE, if age permits, else IGSCE, which is graded upto A.