A distributed denial-of-service (DDoS) attack occurs when multiple compromised computers, often part of a botnet, flood a target server or network with excessive traffic. This overwhelming influx of requests can cause the target to slow down significantly or become completely unavailable to legitimate users. DDoS attacks can disrupt online services, websites, and applications, leading to financial losses and damage to reputation. They are often executed by cybercriminals for various reasons, including extortion, revenge, or simply to cause chaos. Protecting against DDoS attacks typically involves using specialized security measures and traffic management solutions.