Web and File Transfer Protocols

The web and file transfer rely on application-layer protocols that ride on TCP using well-known ports. Learning these protocols and their ports is essential exam material.

This lesson covers HTTP, HTTPS, and the file transfer family: FTP, plus secure alternatives.

HTTP (Hypertext Transfer Protocol) is the language of the web, carrying web pages between browsers and servers. It uses TCP port 80.

HTTP sends data in plain text, so anyone intercepting the traffic could read it. That weakness led to the secure version, HTTPS.

HTTPS (HTTP Secure) is HTTP wrapped in encryption using TLS (Transport Layer Security). It runs on TCP port 443.

HTTPS protects data in transit, so login details and payments stay private. Modern websites use HTTPS by default, and browsers warn when a site uses plain HTTP.

TLS provides encryption, integrity, and server authentication via certificates. The older name was SSL (Secure Sockets Layer), now deprecated but still spoken of loosely.

A certificate proves the server’s identity, while encryption hides the content. Together they make HTTPS trustworthy for sensitive transactions.

FTP (File Transfer Protocol) moves files between hosts. It uses TCP port 21 for control commands and port 20 for the data transfer.

FTP is old and transmits credentials and data in plain text, making it insecure on untrusted networks. It remains common but is being replaced by secure options.

SFTP (SSH File Transfer Protocol) runs over SSH on TCP port 22, encrypting both commands and data. It is a popular secure replacement for FTP.

Despite the similar name, SFTP is not just FTP with security bolted on — it is a different protocol that uses the SSH channel for protection.

FTPS is FTP wrapped in TLS, distinct from SFTP. It adds encryption to the traditional FTP protocol rather than tunneling over SSH.

Both SFTP and FTPS secure file transfers, but they work differently and use different ports. The exam expects you to tell these two apart.

TFTP (Trivial File Transfer Protocol) is a stripped-down transfer protocol using UDP port 69. It has no authentication and minimal features.

TFTP is used on local networks for tasks like loading device firmware or boot images, where simplicity matters more than security or reliability.

Plain HTTP exposes everything in transit, so the web moved decisively to HTTPS. Search engines favor it, and browsers flag HTTP pages as "Not Secure."

As a technician, you will configure certificates and ensure services use 443. Recognizing whether traffic is encrypted is key to assessing security.

Memorize these for the exam:

• HTTP: TCP 80
• HTTPS: TCP 443
• FTP: TCP 20/21
• SFTP: TCP 22 (over SSH)
• TFTP: UDP 69

Notice TFTP is the odd one using UDP; the rest use TCP.

You now know the web protocols (HTTP, HTTPS) and the file transfer family (FTP, SFTP, FTPS, TFTP) with their ports and security properties.

The final lesson covers remote access and mail protocols, completing your map of the everyday services a technician must recognize.

Match protocol to port.

You learned web and file transfer protocols.

• HTTP = TCP 80 (plain text); HTTPS = TCP 443 (TLS encrypted).
• FTP = TCP 20/21, insecure plain text.
• SFTP = TCP 22 over SSH; FTPS = FTP over TLS.
• TFTP = UDP 69, simple and unauthenticated.
• TLS provides encryption, integrity, and server identity via certificates.