Windows Defender is a built-in security solution for Windows 11 that provides real-time protection against malicious threats and viruses. It helps keep your PC secure by monitoring and blocking suspicious activity and removing any malicious software it finds.

Windows Defender monitors all system activity, including programs and files, to detect and prevent malicious activity. If it detects any suspicious activity, it will notify you immediately and take steps to stop it. It also runs background scans at regular intervals to check for potential threats and take swift action before any harm is done.

Windows Defender also includes various layers of protection. For example, it has an advanced firewall that helps protect your system from hackers and malware and a web shield that scans downloaded files for viruses and malware. It also includes various features, like the real-time protection module, which blocks malicious websites from loading. Finally, Windows Defender consists of the network inspection feature, which helps to detect and block malicious network traffic.

In addition to its built-in features, Windows Defender includes access to thousands of third-party security solutions. This means you can opt for extra protection from a trusted source to ensure your system is as secure as possible.

In conclusion, Windows 11 is equipped with Windows Defender, a comprehensive security feature that safeguards the system from malicious threats and viruses. It features an advanced firewall, real-time protection module, and access to thousands of security solutions for optimal protection.