Comments in SQL are annotations within your code that are ignored by the database system when executing queries. They serve as valuable documentation, making your code easier to understand and maintain, especially in larger projects. They are crucial for explaining complex logic, clarifying the purpose of different sections, and helping other developers (or your future self) comprehend the code's functionality. Comments are particularly helpful when working with intricate queries or procedures. They allow you to add explanatory notes directly into the code, enhancing its readability and maintainability. This is a fundamental aspect of writing clean and understandable SQL code.