Which protocol typically runs on port 80?

The correct answer is HTTP, which stands for Hypertext Transfer Protocol. This protocol is the foundation of data communication on the World Wide Web, enabling the transfer of hypertext pages between clients (web browsers) and servers. It is designed for transmitting web pages, and it operates over port 80 by default, allowing users to access websites without needing to specify a port in the URL.

HTTP is essential for web browsing, as it dictates how messages are formatted and transmitted. By using port 80, HTTP facilitates the communication needed for loading resources like text, images, and videos that compose web pages.

Other protocols listed operate on different ports, which is why they do not apply to this question. For instance, FTP (File Transfer Protocol) typically uses port 21 for transferring files, HTTPS (HTTP Secure), which is the secure version of HTTP, operates on port 443, and SMTP (Simple Mail Transfer Protocol) commonly runs on port 25 for sending emails. Understanding the designated ports for these protocols is key for anyone working with network communications.