Which port is commonly used for HTTP traffic?

Port 80 is widely recognized as the standard port for HTTP traffic. When a web browser requests a webpage using the HTTP protocol, it typically communicates over this port, allowing for the transfer of hypertext documents across the internet. This port is foundational for web servers and clients, facilitating the exchange of information without encryption.

Other ports mentioned serve different specific purposes; for instance, Port 21 is used for FTP (File Transfer Protocol), and Port 25 is designated for SMTP (Simple Mail Transfer Protocol), which handles email transmission. Port 443, while it might appear relevant because it is associated with secure web traffic (HTTPS), is not the correct choice when referring specifically to the standard HTTP protocol. Thus, Port 80 remains the definitive answer for HTTP traffic.