What is the best way to retain information from textbooks?

So I realize that the best way to retain information from class is to review the notes over and over again, summarize them, and put a score on them.<br>However, I am taking an online course and the classroom is mostly composed of powerpoints and other reading. I’m wondering what is the best way to retain information from textbooks? Should I treat both of them the same and review, summarize, and score them the same way? Any help is greatly appreciated.