Reading and understanding are not the same activity. You can read every word on a page and retain almost nothing — which is exactly what happens when you read passively, letting the words move across your eyes without your brain working to make sense of them. Active reading is a different process entirely. Before you read, you preview the material: scan headings, look at any diagrams, and ask yourself what you expect to learn. While you read, you pause every few paragraphs to check your understanding by asking: what is the main point here? What is new? What do I not yet understand? After you read, you summarise what you learned in your own words without looking at the text. This pattern — preview, read, pause, summarise — is slower than passive reading but produces several times more retention from the same pages.