The document describes different types of learning units available in the Osh learning app, including: 1. Streams which allow users to choose topics and scroll through cards with images, short texts, and facts to learn. 2. Micro quizzes which test users with 5-7 visual multiple choice questions related to the topic. 3. Recommendations units which show related entities like films, books, people, and apps to the topic for users to explore further.