First of all the marks are different. In Greek schools the best mark you can get is twenty and the worst mark is zero. In German schools it is different too. From the first till the tenth class you get 1-5 (one is the best) and from the tenth class you get 1-15 (15 is the best).
The classes are also split in another way. In Greek schools you go to elementary school (1st – 6th class), then to Junior high school (gymansio) for 3 years and senior high school (lykio) for another 3 years.
Before you go to the next class you take exams in the end of each year.
In German schools you have to do thirteen years, but some regions have changed it to twelve.
Students at German schools have to take exams during the whole year and not in the end.