What type of attack involves overwhelming a system to render it inoperable?

A Distributed Denial of Service (DDoS) attack is designed to overwhelm a target system, such as a server, service, or network, by flooding it with an excessive amount of traffic. The primary goal of a DDoS attack is to disrupt the normal functioning of the targeted system, rendering it inoperable for legitimate users. This type of attack often involves multiple compromised computers, known as a botnet, which collectively send requests or data to the target, causing it to become slow or completely unresponsive.

In contrast, other types of attacks mentioned, such as phishing, spyware, and Trojan attacks, focus on different goals like stealing information, gaining unauthorized access, or manipulating the user's system without immediate network disruption. Phishing attacks seek to deceive individuals into providing sensitive information; spyware secretly gathers user data; and Trojan attacks disguise harmful software as legitimate to gain traction on the system. Therefore, the nature of a DDoS attack specifically aligns with overwhelming the target's resources to disrupt its normal operations.