GrapheneOS is an open-source operating system based on the Android platform, designed to enhance security and privacy for mobile devices. It focuses on providing a minimalistic experience by removing unnecessary features and applications, which reduces potential vulnerabilities. The operating system is compatible with select Google Pixel devices, allowing users to benefit from advanced security features like sandboxing and improved app permissions. GrapheneOS aims to protect user data while maintaining a user-friendly interface, making it a popular choice for privacy-conscious individuals.