There are three distinct forms of distributed denial of service attacks: Attacks that are Based on Volume:  Attacks of this type are also sometimes referred to as Layer3 and 4 attacks. The attacker will attempt to use up all of the available bandwidth on the target website at this stage of the attack. Attacks against the Protocol:  These assaults are quantified in terms of packets per second, and they target both the physical server resources as well as additional components such as load balancers and firewalls. Attacks on the Application Layer:  It encompasses the zero-day DDoS assaults, Slowloris, and other similar programmes that target vulnerabilities in Windows, Apache, or OpenBSD, amongst other systems. Requests per second is the unit used to quantify this.