Performance testing is a type of software testing that evaluates how an application or system behaves under specific workloads. In cybersecurity, performance testing ensures that security mechanisms like firewalls, intrusion detection systems, and authentication services do not degrade system performance or become bottlenecks under heavy traffic. This testing helps identify scalability issues, response times, resource usage, and stability, ensuring that security controls remain effective even during peak usage or cyberattacks. By simulating real-world load and stress conditions, performance testing helps organizations maintain both robust security and optimal user experience.