The different professors have different preferences in how they use this medium to provide you material. Lectures are most effective for you if you use several 'channels' that reinforce each other to pull together the information. You hear the lecturer's voice, which can convey urgency, emphasis, and humor. You see text and interesting images. You take notes, which forces you to use your mind to merge information from these different senses and commit it to paper, using muscles.
Film clips can bring some of the concepts into motion.
It all comes together in lecture. All professors provide outlines of the lecture material. These will be available before class. If last minute changes are made, these will posted after the lecture. These are provided so that you can see the overall plan of the lecture and how it fits together before and during the lecture itself.