Internet Basics for IBPS PO — Protocols, URLs, DNS, and Web Services

beginner 18 min read

Concept

Think of the internet as a massive postal system for digital information. Just like the postal system needs addresses, delivery rules, and sorting offices — the internet needs IP addresses, protocols, and DNS servers.

Here is the core picture: your computer connects to the internet through an ISP (Internet Service Provider — companies like BSNL, Jio, Airtel). Once connected, every piece of data you send or receive follows a specific protocol — a pre-agreed set of rules for how the conversation happens. Different tasks need different protocols, just like you use different postal services for letters, parcels, and speed post.

The World Wide Web (WWW) is not the same thing as the internet — this distinction catches people. The internet is the underlying physical and logical infrastructure (cables, routers, servers). The WWW is a service that runs on top of it — a collection of interlinked web pages you access through a browser (Chrome, Firefox, Edge). Other services — email, file transfer, video streaming — also run on the internet but are not part of the WWW.

A URL (Uniform Resource Locator) is the address you type into a browser. Every URL maps to an IP address through the DNS (Domain Name System), which works exactly like a phonebook: you know a name (google.com), DNS gives you the number (142.250.x.x). Without DNS, you would need to memorize numeric IP addresses for every website — impractical at scale.

For IBPS PO Computer Awareness, this entire chapter reduces to two things: knowing what each abbreviation stands for, and knowing which protocol does which job. Questions rarely go deeper than that. The next section gives you the complete map.


Deep Dive

The Protocol Stack — Who Does What

This is the heart of every question in this chapter. Learn this table cold.

| Protocol | Full Form | Job | Default Port | |---|---|---|---| | HTTP | HyperText Transfer Protocol | Web browsing (unsecured) | 80 | | HTTPS | HyperText Transfer Protocol Secure | Web browsing (SSL/TLS encrypted) | 443 | | FTP | File Transfer Protocol | Transferring files between computers | 21 | | SMTP | Simple Mail Transfer Protocol | Sending email | 25 | | POP3 | Post Office Protocol version 3 | Receiving email (downloads to device) | 110 | | IMAP | Internet Message Access Protocol | Receiving email (stays on server) | 143 | | DNS | Domain Name System | Translating domain names to IP addresses | 53 | | DHCP | Dynamic Host Configuration Protocol | Automatically assigning IP addresses | 67/68 |

The most tested distinction is SMTP vs POP3. SMTP is the outgoing mail protocol — it pushes your email from your client to the server and onward to the recipient's server. POP3 is the incoming mail protocol — it pulls email from the server down to your device. Think: SMTP = Sending, POP3 = Pulling mail in.

HTTP vs HTTPS — The Security Layer

HTTP transmits data in plain text. Anyone intercepting the traffic can read it. HTTPS adds an SSL/TLS (Secure Sockets Layer / Transport Layer Security) encryption layer on top of HTTP. This is why banking websites always use HTTPS — data integrity and confidentiality are guaranteed.

Look at any browser address bar: a padlock icon means HTTPS (port 443). No padlock, or a warning symbol, means HTTP (port 80) or an invalid certificate.

DNS — The Internet's Phonebook

When you type www.sbi.co.in, your browser does not inherently know where that server is. The resolution chain works like this:

  1. Your browser checks its local cache — has it seen this domain before?
  2. If not, it asks your ISP's DNS Resolver.
  3. The resolver queries a Root Name Server, which points to the .in TLD (Top Level Domain) Name Server.
  4. That TLD server points to SBI's Authoritative Name Server, which returns the actual IP address.
  5. Your browser connects to that IP.

This entire chain typically completes in under 100 milliseconds. For the exam, the key fact is: DNS translates human-readable domain names into IP addresses.

URL Anatomy

A full URL looks like this:

https://www.sarkaririse.com/ibps-po/computer?topic=internet#section1

Breaking it down:

The exam almost always tests the full form: Uniform Resource Locator. The trap option is "Universal Resource Locator" — it is wrong. Uniform, not Universal.

Key Internet Services Beyond the Web

HTML Anchor Tag

The <a> tag (anchor tag) creates hyperlinks in HTML. The syntax is:

<a href="https://destination.com">Link Text</a>

The href attribute specifies the destination. Common trap: students confuse <link> (which links external CSS files) with <a> (which creates clickable hyperlinks). They are completely different HTML elements.


Memory Tricks & Shortcuts

patternSMTP Sends, POP3 Picks Up

For every email protocol question, assign a job using the first letters: SMTP = Sending outgoing mail. POP3 = Picking up/Pulling incoming mail. When you see options with SMTP, HTTP, POP3, FTP — eliminate HTTP (web browsing) and FTP (files) first, then apply S=Sending, P=Pulling to pick between SMTP and POP3. This reduces a 4-option question to a 2-second decision. Standard reading + elimination: 30s. With this pattern: 8s.

patternPort Number Pattern: 80-443-21-25

Memorize ports as a ranked sequence: 80 (HTTP, like "H-8-0"), 443 (HTTPS — 4 digits because it is more "secure" and complex), 21 (FTP — "2 computers, 1 transfer"), 25 (SMTP — "2 and 5, send it live"). The exam gives you 4 options that mix these ports. If you know the sequence cold, you eliminate in under 5 seconds. Without the sequence, you are guessing among 4 plausible numbers. That is the difference between 5s and 25s per question.

eliminationURL = Uniform (Never Universal)

Every time you see a URL full-form question, the trap option is "Universal Resource Locator." Strike it out first — it has never been correct. The correct answer is always Uniform Resource Locator. This single elimination removes one wrong option before you read the other three, saving roughly 10 seconds of consideration time on a question that should take 5 seconds total.

patternDNS = Digital Phonebook

When a question describes "translating domain names to IP addresses" or "mapping human-readable names to numeric addresses," that is DNS — always. No other protocol does this job. If you see options with DNS, DHCP, HTTP, FTP: DHCP assigns IPs dynamically (different job), HTTP/FTP are application protocols. DNS is the only name-to-IP translator. Recognition time: 3 seconds flat once the pattern is locked.

eliminationAnchor vs Link Tag Elimination

HTML hyperlink questions always include <link> as a distractor. Eliminate it immediately: <link> connects stylesheets (CSS), not clickable hyperlinks. Similarly, <href> and <url> are not HTML tags at all — they are attributes or concepts. Only <a> is a valid hyperlink element. Spotting and eliminating the two non-tags (<href>, <url>) takes 3 seconds; you are left with <a> vs <link>, and the stylesheet-vs-hyperlink distinction finishes the job. Total: 8s vs 20s for reading all options carefully.


Fast-Solving Framework

When you see an Internet Basics question in the exam hall, run this decision tree:

Step 1 — Is it an abbreviation question? (What does X stand for?) Recall the full form directly. Watch for the "Uniform vs Universal" trap in URL. Watch for "Data Network System" vs "Domain Name System" in DNS.

Step 2 — Is it a protocol-function question? (Which protocol does X?) Map the job: web browsing = HTTP/HTTPS, sending email = SMTP, receiving email = POP3, file transfer = FTP, name-to-IP translation = DNS.

Step 3 — Is it a port number question? (Default port for X?) HTTP=80, HTTPS=443, FTP=21, SMTP=25. These four cover 95% of port questions.

Step 4 — Is it an HTML tag question? Hyperlinks = <a> tag with href attribute. Eliminate <link>, <href>, <url> as tags.

Step 5 — Is it a security question? HTTPS uses SSL/TLS encryption. HTTP is unsecured. Bank websites must use HTTPS.

Total decision time per question: 10-15 seconds. This chapter should be full marks — there is no calculation, only recall.


Solved PYQs

Why this question: Tests the single most-tested HTML fact in IBPS PO Computer Awareness — confusing <a> with <link> or href.

Previous Year Questionपिछले वर्ष का प्रश्न
Which HTML tag is used to create hyperlinks?
HTML में हाइपरलिंक बनाने के लिए कौन सा टैग इस्तेमाल किया जाता है?
Solutionसमाधान

Solving path: Eliminate <href> and <url> first — these are not HTML tags, they are an attribute and a concept respectively. Now you have <link> vs <a>. Recall: <link> connects external resources like CSS stylesheets. <a> creates clickable hyperlinks using the href attribute as destination. Answer: <a>.


Why this question: The FTP vs HTTP distinction is a standard IBPS PO trap — students associate "internet" with HTTP and miss that file transfer has its own protocol.

Previous Year Questionपिछले वर्ष का प्रश्न
Which internet service is primarily used for file transfer between computers?
कंप्यूटरों के बीच फाइल ट्रांसफर के लिए मुख्य रूप से कौन सी इंटरनेट सेवा उपयोग की जाती है?
  1. HTTP
  2. SMTP
  3. FTP
  4. POP3
  1. HTTP
  2. SMTP
  3. FTP
  4. POP3
Solutionसमाधान
FTP (File Transfer Protocol) is specifically designed for transferring files between computers over a network. HTTP is for web browsing, SMTP for sending emails, and POP3 for receiving emails.
FTP (फाइल ट्रांसफर प्रोटोकॉल) विशेष रूप से नेटवर्क पर कंप्यूटरों के बीच फाइलों को स्थानांतरित करने के लिए डिज़ाइन किया गया है। HTTP वेब ब्राउज़िंग के लिए है, SMTP ईमेल भेजने के लिए है।

Solving path: HTTP = web pages. SMTP = sending email. POP3 = receiving email. The question asks specifically about file transfer between computers — that is exactly what FTP was designed for. No overlap with the other three. Answer: FTP.


Why this question: SMTP vs POP3 is the most commonly confused pair in this chapter. The exam exploits this confusion directly.

Previous Year Questionपिछले वर्ष का प्रश्न
Which protocol is used for retrieving emails from a mail server?
मेल सर्वर से ईमेल प्राप्त करने के लिए कौन सा प्रोटोकॉल इस्तेमाल किया जाता है?
  1. SMTP
  2. HTTP
  3. POP3
  4. FTP
  1. SMTP
  2. HTTP
  3. POP3
  4. FTP
Solutionसमाधान
POP3 (Post Office Protocol version 3) is used for retrieving emails from a mail server to a client device. SMTP is used for sending emails, while HTTP is for web browsing and FTP for file transfer.
POP3 (पोस्ट ऑफिस प्रोटोकॉल संस्करण 3) का उपयोग मेल सर्वर से क्लाइंट डिवाइस पर ईमेल प्राप्त करने के लिए किया जाता है। SMTP ईमेल भेजने के लिए उपयोग किया जाता है।

Solving path: The question says "retrieving emails from a mail server" — that means incoming, pulling mail down. SMTP sends outgoing mail. HTTP is web browsing. FTP is file transfer. POP3 is specifically for retrieving/downloading emails from a server to a client. Answer: POP3.


Why this question: Port numbers are a high-frequency topic. This question mixes all four key port numbers as options — designed to trip up candidates who only half-remember them.

Previous Year Questionपिछले वर्ष का प्रश्न
What is the default port number for HTTP communication?
HTTP कम्युनिकेशन के लिए डिफ़ॉल्ट पोर्ट नंबर क्या है?
  1. 21
  2. 25
  3. 80
  4. 443
  1. 21
  2. 25
  3. 80
  4. 443
Solutionसमाधान
Port 80 is the default port for HTTP (HyperText Transfer Protocol) communication. Port 443 is used for HTTPS, port 21 for FTP, and port 25 for SMTP.
पोर्ट 80, HTTP (हाइपरटेक्स्ट ट्रांसफर प्रोटोकॉल) संचार के लिए डिफ़ॉल्ट पोर्ट है। पोर्ट 443 HTTPS के लिए, पोर्ट 21 FTP के लिए, और पोर्ट 25 SMTP के लिए उपयोग किया जाता है।

Solving path: The options 21, 25, 80, 443 correspond to FTP, SMTP, HTTP, HTTPS in that order. The question asks for HTTP's default port — that is 80. Note: 443 is HTTPS (the secure version), not HTTP. Answer: 80.


Why this question: DNS is tested both as a full-form question and a function question. This is the full-form variant — watch the distractor "Data Network System."

Previous Year Questionपिछले वर्ष का प्रश्न
What does DNS stand for in internet terminology?
इंटरनेट की भाषा में DNS का पूरा नाम क्या है?
  1. Data Network System
  2. Domain Name System
  3. Digital Network Service
  4. Data Name Server
  1. Data Network System
  2. Domain Name System
  3. Digital Network Service
  4. Data Name Server
Solutionसमाधान
DNS stands for Domain Name System. It translates human-readable domain names (like google.com) into IP addresses that computers use to identify each other on the network.
DNS का मतलब डोमेन नेम सिस्टम है। यह मानव-पठनीय डोमेन नामों (जैसे google.com) को IP पतों में बदलता है जिनका उपयोग कंप्यूटर नेटवर्क पर एक-दूसरे की पहचान करने के लिए करते हैं।

Solving path: Options include "Data Network System," "Digital Network Service," and "Data Name Server" — all plausible-sounding distractors. The actual function of DNS is translating domain names to IP addresses, making "Domain Name System" the only option where "Domain Name" matches the actual function. Answer: Domain Name System.


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