Diane 35 and Ginette 35 are brand names. Both of them contain exactly the same medicines: cyproterone and ethenyl estradiol. Hence there is no difference between Diane 35 and Ginette 35 except that they are manufactured by two different companies.
These medicines are approved for use in (a) severe acne that do not respond to other medicines and (b) severe hirsutism (hair on face etc of women). Incidentally they also act as oral contraceptives till they are taken.