Codewars is an online programming website which focuses on improving one's programming skill. It has many challenges which train in improving fundamental coding concepts and push you to think critically when approaching a problem. There are different level challenges which range from beginner to master and each challenge is called a kata. One starts as a warrior at war and the battles(challenges) give points that advance ones raking over time. The challenges are adjusted to a rank (Kyu/Dan). These terms are brought from the Japanese system of martial arts. This course is recommended only once you are comfortable with programming concepts.