By actively engaging with the material, your brain has to work. That's learning. Students often learn by rereading a text, highlighting, or writing a summary. This often doesn't work well because it is passive (not active): your brain doesn't do much. To ensure that information is well stored, it is better to actively engage with the material. You remember the information better this way. Actively engaging with information does not mean that the student is busy with the information (this can also mean mindlessly copying information), but it means that the student is actively thinking about the information. Information that you have thought about thoroughly sticks better in your memory. By actively retrieving information from your long-term memory, you strengthen the connections between the neurons in your brain: this makes it easier to retrieve information from your long-term memory (see forgetting curve). Actively engaging with information during the lesson is also beneficial for learning performance (see image). You can engage with the material in various ways. For example, you can create a schema of the study material or test yourself by answering questions. Additionally, you can actively engage with the information you have already learned by trying to write down from memory what you still know. Answering practice questions also helps. Lastly, it helps to make learning enjoyable for yourself. You can assist students in this by regularly asking questions or having students create schemas: make students think. For more information, look at the different learning strategies: retrieval practice, spaced practice, and interleaved practice.
Dewing, J. (2010). Moments of movement: Active learning and practice development. Nurse Education in Practice, 10(1), 22-26.
Roediger, H. L., Putnam, A. L., & Smith, M. A. (2011). Ten benefits of testing and their applications to educational practice. Psychology of learning and motivation, 55, 1-36.