What defines a DDoS (Distributed Denial of Service) attack?

A DDoS (Distributed Denial of Service) attack is defined as a scheme to overwhelm a system with requests. In this type of attack, multiple compromised systems are used to flood a targeted server, network, or service with an overwhelming volume of traffic. This surges beyond the system's capacity to handle requests, leading to service disruption for legitimate users. The goal of a DDoS attack is to incapacitate the target by exhausting its resources such as bandwidth, processing power, or memory.

This definition highlights the nature of DDoS attacks as a malicious attempt to disrupt services rather than anything related to securing data or facilitating authorized access, which distinguishes it from the other options clearly. By understanding that the essence of a DDoS attack lies in the tactics employed to overwhelm systems, one can grasp the significance of network security measures designed to detect and mitigate such threats.