Which component is known as the unique name that appears after the @ sign in email addresses?

The correct answer is the domain name, which is the unique name that appears after the @ sign in email addresses. In an email address such as example@gmail.com, "gmail.com" represents the domain name. This domain is crucial because it indicates the email service provider responsible for handling the delivery of the email to the recipient's inbox.

In addition to being essential for email communications, domain names help differentiate between various organizations and services on the internet. They play a significant role in establishing the identity of the sender and ensuring that messages reach their intended destinations.

Understanding the role of the domain name can also help in recognizing phishing attempts or malicious emails, as a legitimate domain name corresponds to a recognized and trusted organization. In contrast, an unfamiliar or suspicious domain may indicate a potential threat.

The other options, such as IP address, server name, and network ID, while relevant in the context of networking and internet infrastructure, do not pertain to the specific function of identifying or labeling an email address in the way that a domain name does.