Codewars is an online platform that offers coding challenges known as "kata" to help individuals achieve mastery in programming through practice and developer mentorship. Users can choose from a variety of coding challenges ranging from beginner to expert level and solve them using their preferred programming language. Codewars provides an interactive coding environment where users can test their solutions and receive instant feedback. It also offers a vibrant community where users can compare solutions, discuss best practices, and create their own kata to challenge others.