A type of cyberattack targeting applications or websites, denial-of-service (DoS) attacks aim to exhaust the target system’s resources to render it inaccessible to legitimate users.

DDoS attacks may target server vulnerabilities to overload network resources or to consume these resources through the reflection of a high volume of network traffic to the target, or may attempt to overload connection (protocol) or application (compute or storage) resources of the target.

When the overloading traffic originates from more than one source operating in concert, the attack is considered DDoS. Botnets, which are networks of compromised devices – including computers, IoT devices, and servers – are the most common source of DDoS attacks.