What is a denial-of-service (DoS) attack?

A denial-of-service (DoS) attack is characterized by an effort to disrupt the normal functioning of a targeted server, service, or network by overwhelming it with a flood of traffic. This influx of requests can exhaust the resources of the system, causing legitimate users to be unable to access the service or experience significant delays. The goal of such an attack is to render the service ineffectual or completely unavailable, thereby interrupting business operations, frustrating users, and potentially causing financial losses.

Other choices do not align with the definition of a DoS attack. For instance, securing data through encryption relates to protecting information rather than impairing a service, while improving network speed does not involve overwhelming resources. Additionally, normalizing traffic pertains to managing and optimizing data flow rather than disrupting service availability. Therefore, the correct understanding hinges on recognizing that B directly addresses the essence of a DoS attack.