Revision is another word for reviewing.
To understand and remember what you have learned over the year, you need to re-read your course essays, notes and textbooks. Revision requires accurate notes and careful planning to be most effective. It is best to begin your programme of revision two or three months before the exams. Learn.co.uk have developed an online interactive calendar that you can use to create your revision timetable. You can programme it to remind you about your exams and other important events.