Modern web applications incorporate numerous security features to protect user data and maintain system integrity. Common elements include encryption for data transmission, ensuring that sensitive information remains confidential during transmission over networks. Additionally, features like two-factor authentication bolster login security, while firewalls and intrusion detection systems help monitor and defend against unauthorized access. Regular updates and security patches also contribute to safeguarding against newly discovered vulnerabilities, highlighting the importance of a comprehensive security strategy in the development of resilient web applications.