Pull requests in Git are a crucial tool for collaborative development, enabling developers to propose changes, review, and refine them before merging into the main codebase. Platforms like GitHub, GitLab, and Bitbucket use pull requests to ensure structured discussions, streamlined code reviews, and seamless integration of contributions. By leveraging pull requests, teams can maintain code quality, manage version control effectively, and facilitate communication, making them an integral part of modern development practices.