The internet is a global network of interconnected computers that communicate using a shared set of rules called protocols. Think of it like a postal system — your letter (data) needs a language the sender and receiver both understand (protocol), an address (IP address), and a translator if you only know names rather than numbers (DNS).
The World Wide Web (WWW) is not the same as the internet — this distinction trips up a lot of candidates. The internet is the physical infrastructure: cables, routers, servers. The WWW is one service that runs on top of it — a system of interlinked documents (web pages) accessible through a browser. Email, FTP, DNS — all of these are also services running on the internet but are not part of the WWW.
Here's a useful mental map:
For SBI Clerk, this chapter shows up as direct fact-recall. You will be asked which protocol does what, what an abbreviation stands for, which port number maps to which protocol, and what specific HTTP status codes mean. There is almost no calculation involved — it is purely memory-based, which means with the right hooks, you can convert every question in this section into a guaranteed mark.
The key protocols you absolutely must know: HTTP, HTTPS, SMTP, POP3, IMAP, FTP, DNS, DHCP. Know each one's purpose, its port number, and any common trap comparisons (like SMTP vs POP3 for email).
A protocol is a standardised set of rules that defines how data is transmitted and received. Think of it as the agreed-upon language two computers use to talk to each other.
HTTP (HyperText Transfer Protocol) Used to transfer web pages from a server to your browser. When you type a URL and hit Enter, your browser sends an HTTP request to the server. Default port: 80.
HTTPS (HyperText Transfer Protocol Secure) The secure version of HTTP. It adds SSL/TLS encryption on top — meaning the data exchanged between your browser and the server is encrypted. Default port: 443. Any website handling logins or payments should use HTTPS — look for the padlock icon in the browser.
FTP (File Transfer Protocol) Used specifically to transfer files between computers over a network. You use FTP to upload files to a web server or download from one. Default port: 21 (control), 20 (data transfer).
SMTP (Simple Mail Transfer Protocol) Used for sending email. When you click Send in Gmail or Outlook, SMTP is doing the work. Default port: 25 (or 587 for submission). The critical exam point: SMTP is for outgoing mail only.
POP3 (Post Office Protocol version 3) Used for receiving email. It downloads emails from the server to your local device and (by default) deletes them from the server. Default port: 110.
IMAP (Internet Message Access Protocol) Also used for receiving email, but unlike POP3, it syncs the mailbox on the server. You can access the same emails from multiple devices. Default port: 143.
DNS (Domain Name System)
DNS translates human-readable domain names (like www.sbi.co.in) into IP addresses (like 192.168.1.1) that computers actually use to find each other. Without DNS, you would need to remember numeric IP addresses for every website. Default port: 53.
DHCP (Dynamic Host Configuration Protocol) Automatically assigns IP addresses to devices on a network. When your phone connects to a Wi-Fi network, DHCP is what gives it an IP address automatically.
Status codes are three-digit numbers a web server sends back to indicate what happened with your request.
| Code | Meaning | |------|---------| | 200 | OK — request successful | | 301 | Moved Permanently — page has been redirected | | 400 | Bad Request | | 401 | Unauthorised | | 403 | Forbidden | | 404 | Not Found — the resource does not exist on the server | | 500 | Internal Server Error — problem on the server side |
For the exam, focus on 200, 301, 404, and 500 — these four appear most frequently.
A URL (Uniform Resource Locator) is the complete address of a resource on the internet. Breaking down https://www.sbi.co.in/careers/index.html:
https — Protocolwww.sbi.co.in — Domain name/careers/index.html — Path to the specific resourceISP (Internet Service Provider) is the company that gives you internet access — BSNL, Jio, Airtel, etc. Without an ISP, your device has no gateway to the internet.
WWW (World Wide Web) — frequently asked as a full-form question. It is an information system of interlinked hypertext documents accessed via the internet using a browser.
| Protocol | Port | |----------|------| | FTP (data) | 20 | | FTP (control) | 21 | | SMTP | 25 | | DNS | 53 | | HTTP | 80 | | POP3 | 110 | | IMAP | 143 | | HTTPS | 443 |
This table is high-yield — memorise it in full.
The most common trap question pairs SMTP against POP3/IMAP and asks which one sends email.
Pattern: SMTP = Send. POP3/IMAP = receive (Pick up/Access).
Micro-example: "Which protocol sends email?" — You see SMTP, POP3, IMAP, HTTP. The moment you read "send," your brain fires: S = Send = SMTP. Done in under 5 seconds vs. 30 seconds of trying to recall from raw memory.
Step count: Without pattern — recall from memory (3–5 steps, error-prone). With pattern — one letter association (1 step, zero error).
HTTP is plain, port 80. HTTPS is secure (plus SSL layer), port 443.
Association: 80 is the base. 443 is almost exactly 80 × 5 + 43 — but a cleaner hook: think "4-4-3 = Secure (four letters in 'safe' + three extra for encryption)." More practically: 80 → 443 is an upgrade, just as HTTP → HTTPS is an upgrade.
For FTP: ports 20 and 21 come in a pair, data and control — think "20–21, twin ports, file twins."
Standard recall time: 15–20 seconds per port. With these two anchors locked, you retrieve all four in under 8 seconds total.
Every exam repeats some version of "which service converts domain names to IP addresses?" The answer is always DNS.
Anchor: DNS : Domain Names :: Phone Book : Names-to-Numbers. A phone book translates a person's name (domain) into their phone number (IP address). Lock this analogy once; it covers every phrasing of this question.
Distractor watch: DHCP also assigns IP addresses — but to devices on a local network, not by translating domain names. When the question says "translates domain names," it is DNS, not DHCP. Recognising this distinction saves you from the most common wrong answer here.
Standard method (trying to recall the definition): 20 seconds. With the phone-book anchor: 4 seconds.
HTTP status codes follow a group pattern:
If you blank on the exact code, the hundred-digit tells you the category. For the exam, only 200, 301, 404, and 500 are tested — the above pattern eliminates two or three wrong options instantly.
Elimination time: 3 seconds per option vs. 15 seconds of rote recall.
Full-form questions for WWW give distractors that shuffle the word order: "World Web Wide," "Wide World Web," "Web World Wide." Only one sequence is correct — World Wide Web.
Quick test: Say it naturally in a sentence — "I browsed the World Wide Web." You would never say "I browsed the Wide World Web." Natural language order eliminates all distractors in 3 seconds without memorising anything.
This works on any full-form where the real term sounds natural as an English phrase — ISP (Internet Service Provider), URL (Uniform Resource Locator), etc.
When you see an Internet Basics question in the exam hall, run this decision tree:
Step 1 — Is it a full-form question? Yes → read each option aloud mentally. The one that sounds like natural English is almost always correct. (WWW, ISP, URL, DNS, FTP — all read cleanly in order.)
Step 2 — Is it a "which protocol does X" question?
Step 3 — Is it a port number question? Apply the ladder: 20/21 = FTP, 25 = SMTP, 53 = DNS, 80 = HTTP, 110 = POP3, 143 = IMAP, 443 = HTTPS.
Step 4 — Is it an HTTP status code question? Apply the group rule: 2xx = success, 4xx = client error (404 = Not Found), 5xx = server error (500 = Internal Server Error).
Step 5 — Is it about secure vs. non-secure? HTTP = plain, port 80. HTTPS = encrypted (SSL/TLS), port 443. Any question about "secure transmission" or "padlock in browser" points to HTTPS.
Target: every question in this section answered in under 10 seconds.
Why this question: The WWW full-form appears in almost every iteration of banking computer awareness. It tests whether you know WWW is a specific service, not the internet itself.
Solving path: Read each option aloud. "World Wide Web" is natural English. "World Web Wide" and "Wide World Web" invert the adjective order. Eliminate in 3 seconds. Answer: A.
Why this question: SMTP vs. POP3 vs. IMAP is the single most repeated email-protocol question in SBI Clerk and IBPS Clerk papers. Examiners know aspirants confuse sending and receiving.
Solving path: The question says "sending." S = Send = SMTP. POP3 and IMAP are both receiving protocols — eliminate both. HTTP is for web pages — eliminate. Answer: C (SMTP).
Why this question: DNS vs. DHCP is a high-frequency distractor pair. Both deal with IP addresses — but in completely different ways.
Solving path: Key phrase — "translates domain names to IP addresses." DNS is the phone book. DHCP assigns IPs to devices but does not translate names. FTP is file transfer. SMTP is email. Eliminate FTP and SMTP first, then distinguish DNS from DHCP using the "domain names" cue. Answer: B (DNS).
Why this question: ISP full-form tests a basic but frequently missed abbreviation. The distractor "Internet Security Protocol" is designed to catch candidates who confuse ISP with security-related terms.
Solving path: ISP = the company that gives you internet access. Jio, BSNL, Airtel — all ISPs. "Internet Service Provider" is the only option that matches this real-world function. "Internet Security Protocol" sounds plausible but ISP is not a security term. Answer: A.
Why this question: HTTP status code 404 is tested because it is universally encountered but frequently confused with 400 (Bad Request) or 500 (Server Error).
Solving path: Apply group rule — 4xx codes are client-side errors. 404 specifically = resource not found on the server. 200 = success (eliminate immediately). 301 = redirect (eliminate). 500 = server error, not "not found" (eliminate). Answer: C (404).
Why this question: FTP vs. HTTP is a common confusion — both transfer data, but for very different purposes.
Solving path: "File transfer" is the specific phrase. FTP = File Transfer Protocol — the name itself contains the answer. HTTP transfers web pages, not generic files. SMTP is email. DNS is name resolution. Answer: C (FTP).
Why this question: Secure vs. non-secure protocol is a recurring theme in SBI Clerk computer sections. HTTPS appears both as a direct question and embedded in browser-security questions.
Solving path: "Secure data transmission" + "SSL/TLS encryption" = HTTPS. HTTP is the non-secure version. FTP has a secure variant (SFTP) but FTP itself is not secure and is not the primary choice here. SMTP is email. Answer: B (HTTPS).
Why this question: Port numbers are tested directly. Port 80 is the most commonly asked, with 443 (HTTPS) as a close second.
Solving path: Port 21 = FTP (eliminate). Port 25 = SMTP (eliminate). Port 80 = HTTP (correct). Port 443 = HTTPS. Since the question asks for HTTP specifically (not HTTPS), answer is 80, not 443. Answer: C (80).
Confusing WWW with the internet. The internet is the infrastructure; the WWW is one service on it. Questions sometimes ask "what is the internet?" with "WWW" as a distractor — they are not the same thing.
Choosing IMAP or POP3 for "sending" email. Both are receiving protocols. Only SMTP sends. This is the single most common wrong answer in email-protocol questions.
Mixing up DNS and DHCP. DNS translates domain names to IPs. DHCP assigns IPs to devices automatically. When a question mentions "domain name," it is always DNS. When it says "assigns IP addresses to devices on a network," it is DHCP.
Selecting HTTP instead of HTTPS for secure transmission. Any question with the words "secure," "encrypted," "SSL," or "TLS" is pointing at HTTPS (port 443), not HTTP (port 80). The two options are almost always paired as distractors.
Confusing 404 (Not Found) with 500 (Internal Server Error). Both are error codes, but 404 means the specific resource does not exist — the server is working fine but cannot find what you asked for. 500 means the server itself has a problem.
Reporting FTP port as just "21." FTP uses two ports: 20 for actual data transfer and 21 for control commands. If the question specifies "control connection" or just "FTP port," the answer is 21. If it specifies "data transfer," it is 20. When the question is ambiguous, 21 is the safer default — but know both.