Snyk is a developer security tool that helps developers build secure applications without needing to be security experts themselves. It offers various tools and integrations to improve security, including static analysis for code vulnerabilities in IDEs, pre-commit and CI integrations through the CLI, easy dependency management, online code checking, and continuous learning opportunities. By using Snyk, developers can find and fix security vulnerabilities quickly, reduce development time, and stay up-to-date with the latest security best practices.