About DoS and DDoS attacks
A denial of service (DoS) occurs when an attacker overwhelms server resources by flooding a target system with anomalous data packets, rendering it unable to service genuine users. A distributed denial of service (DDoS) occurs when an attacker uses a master computer to control a network of compromised systems, otherwise known as a ‘botnet’, which collectively inundates the target system with excessive anomalous data packets.