A DDoS (Distributed Denial of Service) attack is a malicious attempt to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of internet traffic. Attackers often use multiple compromised systems to launch these attacks, making them difficult to mitigate. DDoS attacks significantly affect websites by causing downtime, slowing performance, and preventing legitimate users from accessing services. Businesses can lose revenue and suffer reputational damage due to these interruptions, highlighting the need for effective security measures.