Computer ScienceCBSE Class 12 · Data Communication

Network Protocols: HTTP, HTTPS, FTP, PPP, SMTP, POP3, TCP/IP, TELNET and VoIP (Class 12 Computer Science)

Updated 17 October 2026 · Fact-checked

A protocol is a set of rules for communication between devices. HTTP and HTTPS transfer web pages (HTTPS in encrypted form), FTP transfers files, SMTP sends email and POP3 receives it, TELNET gives remote login, PPP connects two nodes directly, TCP/IP governs data delivery on the Internet, and VoIP carries voice and video calls over the Internet.

Notice that SMTP only pushes mail forward from sender to servers, while POP3 is the last step that pulls mail down to the receiver.

Illustration drawn for QuestionBuddy.

Understand Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP

A protocol is an agreed set of rules for exchanging data; both devices must follow the same protocol. The CBSE list is learnt by full form and one-line job.

HTTP (HyperText Transfer Protocol): transfers web pages between a web server and a browser.
HTTPS (HyperText Transfer Protocol Secure): HTTP with encryption, so the data cannot be read on the way; used for payments and logins.
FTP (File Transfer Protocol): uploads and downloads files between computers.
PPP (Point-to-Point Protocol): sets up a direct connection between two nodes, for example a computer and an Internet service provider over a dial-up or similar link.
SMTP (Simple Mail Transfer Protocol): sends email from the sender's mail client to the mail server and between servers.
POP3 (Post Office Protocol, version 3): lets a mail client retrieve (download) email from the mailbox on the mail server.
TCP/IP (Transmission Control Protocol / Internet Protocol): the basic suite of the Internet. TCP breaks the data into packets, numbers them and reassembles them in order at the destination, checking for loss. IP addresses each packet and routes it to the destination.
TELNET: remote login, which lets a user work on a distant computer as if on a terminal connected to it.
VoIP (Voice over Internet Protocol): carries voice (and video) calls over the Internet as packets instead of using the telephone network.

Email path. The sender's client uses SMTP to send the mail; the receiver's client uses POP3 to collect it.

Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP: key facts

Web and files: HTTP transfers web pages
HTTPS HTTP with encryption, secure
FTP transfers files; Use HTTPS for payments.
Mail and login: SMTP sends email
POP3 receives (downloads) email
TELNET remote login to another computer; Send = SMTP, receive = POP3.
Internet and links: TCP/IP TCP splits and reassembles packets, IP addresses and routes
PPP direct point-to-point link between two nodes
VoIP voice and video calls over the Internet; TCP/IP is the base of the Internet.
Full forms: HTTP HyperText Transfer Protocol
FTP File Transfer Protocol
SMTP Simple Mail Transfer Protocol
POP3 Post Office Protocol version 3
PPP Point-to-Point Protocol
VoIP Voice over Internet Protocol; Spelling matters for the mark.

HTTP	transfers web pages
HTTPS	HTTP with encryption, secure
FTP	transfers files

SMTP	sends email
POP3	receives (downloads) email
TELNET	remote login to another computer

TCP/IP	TCP splits and reassembles packets, IP addresses and routes
PPP	direct point-to-point link between two nodes
VoIP	voice and video calls over the Internet

HTTP	HyperText Transfer Protocol
FTP	File Transfer Protocol
SMTP	Simple Mail Transfer Protocol
POP3	Post Office Protocol version 3
PPP	Point-to-Point Protocol
VoIP	Voice over Internet Protocol

How to answer Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP questions

For a protocol question, answer with the name, the full form and the job.

1If the question gives a job, find the protocol: web page, file, send mail, receive mail, remote login, secure web, direct link, Internet voice call.
2If it gives a protocol, expand it and add a one-line job.
3For HTTP versus HTTPS write: both fetch web pages; HTTPS adds encryption and is used for sensitive data.
4For a case study, assign one protocol to each step of the story (send, receive, secure, transfer).
5For TCP/IP, name the job of each half: TCP reassembles and checks; IP addresses and routes.

Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Sending a homework mail

Suppose Asha emails her homework to the teacher, and the teacher opens it in a mail program on her own computer.

Which protocol sends the mail, and which one lets the teacher's program collect it?

Try it first, then show the solutionSolution

Sending from Asha's program to the mail server: SMTP.
Collecting from the mailbox on the server: POP3.

Answer: SMTP sends; POP3 receives.

Memory hook: S for send; P for pick up.

Paying a school fee online

Suppose a parent opens the fee page of a school and the address begins with https.

Why is https preferred to http for this page?

Try it first, then show the solutionSolution

HTTP sends data as plain text which could be read on the way.
HTTPS encrypts the data, so card details are protected.

Answer: HTTPS encrypts the data, so it is secure.

Memory hook: The S stands for secure.

Tricks to remember Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP

Short memory aids. Say each one aloud once, then use it on a question the same day.

S sends, P picks up
SMTP sends mail; POP3 picks it up.
Use it when: Mail protocols.
HTTP + S = secure
HTTPS is HTTP plus secure encryption.
Use it when: HTTP versus HTTPS.
F-ile = FTP, Tel-net = telephone-like remote
FTP files; TELNET lets you operate a remote machine.
Use it when: FTP versus TELNET.
TCP tidies, IP addresses
TCP splits and reassembles; IP addresses and routes.
Use it when: TCP/IP job split.

Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Mail protocol · 1 mark · MCQBoard level

Which protocol is used to send an email?
(a) POP3 (b) SMTP (c) FTP (d) TELNET

Try it first, then show the solutionSolution

Sending uses the Simple Mail Transfer Protocol.

Answer: (b) SMTP

Example 2: Full forms · 2 marks · Short answerBoard level

Write the full forms of HTTP, FTP and POP3.

Try it first, then show the solutionSolution

HTTP: HyperText Transfer Protocol. FTP: File Transfer Protocol. POP3: Post Office Protocol, version 3.
Award marks for the correct expansion of all three.

Answer: HyperText Transfer Protocol; File Transfer Protocol; Post Office Protocol version 3

Example 3: Name the protocol · 3 marks · Short answerHarder board level

Name the protocol used for: (i) uploading a file to a website's server; (ii) logging in to a remote computer; (iii) a voice call over the Internet.

Try it first, then show the solutionSolution

(i) FTP. (ii) TELNET. (iii) VoIP.
One mark for each correct protocol.

Answer: (i) FTP (ii) TELNET (iii) VoIP

Example 4: HTTP and HTTPS · 3 marks · Short answerHarder board level

Differentiate between HTTP and HTTPS and state which one a bank website should use.

Try it first, then show the solutionSolution

HTTP transfers web pages as plain text, so data can be read on the way. (1 mark)
HTTPS is HTTP with encryption, so the data is protected. (1 mark)
A bank site should use HTTPS, because it handles sensitive data. (1 mark)

Answer: HTTPS adds encryption; the bank should use HTTPS.

Example 5: Case: an email story · 4 marks · Case-basedHOTS / competency

Suppose Ravi sends a project file as an email attachment to Meena, then opens a video call with her.
(i) Which protocol sends Ravi's email? (1 mark)
(ii) Which protocol lets Meena's program receive it? (1 mark)
(iii) The email data is broken into packets and reassembled at Meena's end. Which protocol does this? (1 mark)
(iv) Which technology carries the video call over the Internet? (1 mark)

Try it first, then show the solutionSolution

(i) SMTP.
(ii) POP3.
(iii) TCP (of TCP/IP) splits the data into packets and reassembles them.
(iv) VoIP.

Answer: (i) SMTP (ii) POP3 (iii) TCP/IP (TCP) (iv) VoIP

Where students lose marks in Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP

The slips examiners see most often, and what to write instead.

Mistake: Mixing SMTP and POP3
SMTP sends; POP3 receives.
Wrong working
POP3 is used to send email.
Right working
SMTP sends email; POP3 receives email.
Do this: Remember: S for send.
Usually costs: 1 mark
Mistake: Writing a wrong full form for TCP/IP
TCP is Transmission Control Protocol and IP is Internet Protocol.
Wrong working
Transfer Control Protocol / Internet Provider
Right working
Transmission Control Protocol / Internet Protocol
Do this: Write each half separately.
Usually costs: 1 mark
Mistake: Giving HTTP as the secure protocol
The secure version is HTTPS.
Wrong working
HTTP is used for secure web pages
Right working
HTTPS is used for secure web pages
Do this: The S means secure.
Usually costs: 1 mark

Exam tips

Write the full form first, then the job.
Match the story steps to protocols one by one in case studies.
In HTTP versus HTTPS write the word encryption.
For TCP/IP split the jobs: TCP packetises and reassembles, IP addresses and routes.
VoIP is the answer to Internet voice or video call questions.

Practice questions on Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
The protocol used to transfer files between computers is:
(a) HTTP (b) FTP (c) SMTP (d) PPP
Hint
Think of file in the name.
Answer
(b) FTP
Q2 · 1 mark · Very short answerBoard level
What does VoIP stand for?
Hint
Voice, Internet and Protocol.
Answer
Voice over Internet Protocol
Q3 · 2 marks · Short answerHarder board level
Write two differences between SMTP and POP3.
Hint
Think send versus receive.
Answer
SMTP sends email from the client to the mail server (and between servers); POP3 retrieves email from the mailbox on the server to the client.
Q4 · 1 mark · Assertion-reasonHarder board level
Assertion (A): HTTPS is safer than HTTP for online payments.
Reason (R): HTTPS encrypts the data exchanged between the browser and the server.
(a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is not the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.
Hint
The S in HTTPS stands for secure.
Answer
(a) Both are true and R explains A.
Q5 · 3 marks · Short answerHOTS / competency
Suppose a company wants its staff in two cities to hold video meetings over the Internet without using telephone lines, and also to download large reports from a central computer. Name two protocols or technologies and the job of each.
Hint
One for calls and one for files.
Answer
VoIP carries voice and video calls over the Internet as packets. FTP uploads and downloads files from the central computer. (TCP/IP underlies both by delivering the packets.)

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.What does FTP do?Show answer
Transfers files between computers.
2.What does SMTP do?Show answer
Sends email.
3.What does POP3 do?Show answer
Retrieves email from the mail server.
4.What does TELNET do?Show answer
Remote login to another computer.
5.What does PPP do?Show answer
Provides a direct point-to-point connection between two nodes.
6.What does HTTPS add to HTTP?Show answer
Encryption (security).

Network Protocols: HTTP, HTTPS, FTP, SMTP, POP3, TCP/IP, TELNET, VoIP, PPP: frequently asked questions

What is the difference between HTTP and HTTPS?

Both transfer web pages. HTTPS adds encryption, so the data between browser and server cannot easily be read by others; use it for logins and payments.

Which protocol sends and which receives email?

SMTP sends email and POP3 receives (downloads) it.

What are TCP and IP?

TCP breaks the data into packets and reassembles them with checks; IP gives each packet an address and routes it. Together they run the Internet.

Is the full form of PPP asked?

Yes, PPP is in the list: Point-to-Point Protocol, a direct connection between two nodes such as a computer and a service provider.