Why You Shouldn’t Use Udemy : My Personal Thoughts
Would it occur to you to consider making money by offering a course for sale online? If this is the case, there's a good possibility you've looked into Udemy as well.
If you've never heard of Udemy, it's a platform for creating and selling online courses. A new course is added to their library when you create it. Udemy gets a cut of the sale if your course is purchased by a visitor.
Although there's more to it, this gives you a good idea of the big picture.