CalyxOS is an open-source operating system designed for mobile devices, focusing on privacy and security. It is based on the Android platform but offers enhanced features that protect user data and limit tracking. Users can install it on compatible smartphones, providing a more secure alternative to standard operating systems. The system includes built-in privacy tools, such as a firewall and app permissions management, allowing users to control their data. Additionally, CalyxOS supports the installation of applications from various sources, including the F-Droid repository, which features privacy-respecting apps.