Application security refers to the processes, tools, and practices used to protect software applications from threats and vulnerabilities throughout their lifecycle. This includes measures taken during development, deployment, and maintenance to prevent unauthorized access, data breaches, and other cyberattacks. Common strategies involve code reviews, security testing, vulnerability scanning, and the use of firewalls or encryption. By integrating security into every phase of application development, organizations can reduce risks and ensure the confidentiality, integrity, and availability of their software and data.