How does the Irish school system work?

Irish (Republic) School System: PRIMARY SCHOOL Age 4-5 : Junior Infants Age 5-6 : Senior Infants Age 6-7 : 1st Class Age 7-8 : 2nd Class Age 8-9 : 3rd Class Age 9-10 : 4th Class Age 10-11: 5th Class Age 11-12 : 6th Class SECONDARY SCHOOL Age 12-13 : 1st Year Age 13-14 : 2nd Year Age 14-15 : 3rd Year (Junior Certificate Exam - June) Age 15-16 : 4th Year/Transition Year (Optional in Some Schools) Age 16-17 : 5th Year Age 17-18 : 6th Year (Leaving Certificate Exam - June) University/College/Employment (18+)