In the top right of the content editor interface you will find a number of different content types that can be selected. While these do not change how the content performs, they will be shown to the user if they take the course on Next Tech.
Here is how Next Tech categorizes its content:
Activity: Activities are designed to guide the user through learning a new subject area by giving them opportunities to apply the skills in a real-world scenario. In larger courses, activities are typically focused on the application of concepts learned in lessons, but in shorter courses, they may also teach new material as the user progresses.
Challenge: Challenges typically include only a problem statement for the user to solve and some starter code and/or environment. This allows the user to focus on solving the problem they've been tasked with.
Lesson: Lessons are used to introduce new subject matter to the user alongside an environment where they can test out new skills if they'd like, but guided hands-on application is typically reserved for activities.
Project: Projects are open-ended opportunities for the user to apply what they have learned so far. At most, they may contain a short suggestion for what the user could build and some starting code to work with, but beyond that, the user is on their own to build something new!
Reading: A reading is used to share static markdown with the user. Like a quiz, it can be helpful to disable the sandbox environment when creating a reading to save on costs.