Online Judges are platforms that allow users to practice and improve their programming skills by solving coding problems. These platforms provide a variety of challenges, ranging from simple tasks to complex algorithms, and automatically evaluate the submitted solutions for correctness and efficiency. Popular examples of online judges include LeetCode, HackerRank, and Codeforces. Users can compete in contests, track their progress, and learn from others by viewing different solutions. Online judges often support multiple programming languages, making it accessible for a wide range of users, from beginners to experienced developers looking to sharpen their skills.