Revision and lectures
Revision is about re-visiting material. It involves thinking about the information, synthesising it and beginning to understand concepts that are being explored. Attending and listening to a lecture is not enough, and is generally not a learning experience in itself.
You need to make notes during the lecture, engage in the thoughts and ideas that are presented, talk and discuss the topic with others on the course.
You need to then do something with your notes, engage in extra reading and study and work all this up into your own personal guide to, and thoughts about, the subject. How you go about this, and what your personal guide looks like depends in part on your preferred way of learning.