Firefox is an open-source web browser developed by the Mozilla Foundation and Mozilla Corporation. It is available for multiple operating systems, including Windows, macOS, Linux, Android, and iOS. Firefox is known for its emphasis on user privacy, security, and customization. It provides a fast and feature-rich web browsing experience, supports a wide range of extensions and add-ons, and offers tools like Enhanced Tracking Protection to enhance privacy. Users can also synchronize their browsing data across devices using Firefox Sync. As an open-source project, Firefox benefits from community-driven development and contributions, making it a popular choice among users seeking a flexible and privacy-focused web browser.