Teachable is a popular platform for creating and selling online courses. It offers a range of features for course creators, such as the ability to upload video, audio, and text-based content, as well as the ability to create quizzes and surveys. Additionally, it provides tools for managing students, including the ability to enroll students, track progress, and provide feedback. It also allows course creators to set their own pricing, making it a great option for educators and experts looking to monetize their knowledge.