Online coding platforms are websites or applications that provide tools and resources for learning and practicing programming skills. They often offer interactive coding exercises, tutorials, and challenges that cater to various skill levels, from beginners to advanced programmers. Popular platforms include Codecademy, LeetCode, and HackerRank. These platforms typically feature a community aspect, allowing users to share their solutions, ask questions, and collaborate on projects. Many also provide coding competitions and job placement opportunities, making them valuable for both learning and career advancement in the tech industry.