Which type of attack involves overwhelming a system with traffic?

A Denial of Service (DoS) attack is characterized by overwhelming a system, network, or service with excessive traffic, rendering it unusable for legitimate users. The primary goal of a DoS attack is to disrupt the normal functioning of a targeted service, often leading to downtime, loss of revenue, reputational damage, or other factors that affect an organization negatively. Attackers may utilize various methods, such as sending massive volumes of requests or exploiting vulnerabilities, to flood the target and exhaust its resources, which prevents it from responding to genuine requests from users.

In contrast, other types of attacks mentioned do not focus on overwhelming a system with traffic. Phishing attacks are aimed at tricking users into providing sensitive information, while Man-in-the-Middle attacks involve intercepting communications to manipulate or steal data. SQL injection attacks exploit vulnerabilities in a web application by inserting malicious SQL code into an input field but do not primarily involve overwhelming the server with traffic.