Lessons are pages in a virtual textbook, organized into chapters, or modules.
Let's talk about lesson ingredients, then how ingredients are mixed together.
Lessons have text and images, like a textbook, but they have so much more. They have videos.
They have multiple-choice and fill-in-the-blank questions.
They have open-ended questions.
That screen shot shows another ingredient, a character. I use characters to simulate students taking the course, along with the real students. Characters do worked examples, ask questions, model social interaction, and more.
Lessons can have simulations, calculators, sandboxes... whatever makes sense for your course. Here's a sandbox for a web tech course.
Lessons have exercises embedded in them.
Mixing lesson ingredients
You mix ingredients to create a good student experience. Many of my lessons have this structure:
Activate prior knowledge with questions.
Position the lesson within the course
Lesson body. A mixture of direct explanations with schemas, worked examples, and exercises. Mix other ingredients to taste.
There's more on lesson structure in the SCDM.