A web browser (Hindi: वेब ब्राउज़र / जाल विचरक) is application software that fetches web pages from servers over the internet and displays them. It understands HTML (structure), CSS (style) and JavaScript (behaviour). The browser is a client; the website runs on a server.
What happens when you type codekilla.com and press Enter
- IURL parsing — https (protocol) :// codekilla.com (domain) /courses (path) ?lang=hi (query) #top (fragment).
- IIDNS lookup — the browser asks a DNS server (like a phone book) for the IP address of codekilla.com → e.g. 104.21.x.x. Checked in browser cache → OS cache → router → ISP → root/TLD/authoritative servers.
- IIITCP handshake + TLS handshake — a secure connection is made (the padlock icon; HTTPS = HTTP + encryption, port 443; plain HTTP uses port 80).
- IVHTTP request — GET /courses HTTP/2 with headers (cookies, user-agent, accept-language).
- VServer responds — status code (200 OK, 301 redirect, 404 not found, 500 server error) + HTML.
- VIRendering — HTML → DOM tree, CSS → CSSOM, combined into the Render Tree → Layout (positions) → Paint (pixels) → Composite. JavaScript runs in the engine (V8 in Chrome/Edge, SpiderMonkey in Firefox, JavaScriptCore in Safari).
- VIIMore requests — images, fonts, scripts, API calls; caching stores them for next time.
Browser history
| Year | Browser | Maker | Note |
|---|---|---|---|
| 1990 | WorldWideWeb (Nexus) | Tim Berners-Lee | First browser AND editor; ran on NeXT |
| 1992 | Lynx | University of Kansas | Text-only; still exists |
| 1993 | Mosaic | NCSA (Marc Andreessen) | First popular graphical browser — images inline |
| 1994 | Netscape Navigator | Netscape | 90% market share in 1995; gave us JavaScript, cookies, SSL |
| 1995 | Internet Explorer 1.0 | Microsoft | Bundled with Windows; won the 'First Browser War'; IE6 (2001) had 95% share; retired 15 June 2022 |
| 1996 | Opera | Opera Software (Norway) | Invented tabs (1994 MultiTorg), speed dial, built-in VPN |
| 2003 | Safari | Apple | Default on Mac & iPhone; WebKit engine |
| 2004 | Mozilla Firefox | Mozilla Foundation | Open source, from Netscape's code; Gecko engine |
| 2008 | Google Chrome | V8 engine, sandboxed tabs; ~65% share today; Chromium is its open-source base | |
| 2015 | Microsoft Edge | Microsoft | Replaced IE; switched to Chromium in 2020 |
| 2016 | Brave | Brendan Eich (creator of JavaScript) | Blocks ads & trackers by default |
| 2016 | Vivaldi | Jon von Tetzchner (Opera co-founder) | Power-user features |
| 2017 | Samsung Internet | Samsung | Default on Galaxy phones |
| 2019 | Tor Browser (2008 → mainstream) | Tor Project | Anonymity via onion routing |
| 2022 | Arc | The Browser Company | Sidebar tabs, spaces |
| 2024–25 | AI browsers | Perplexity Comet, OpenAI Atlas, Dia, Chrome with Gemini, Edge Copilot | Browser agents that read and act on pages |
Parts of a browser
| Part | Job |
|---|---|
| Address bar / Omnibox | Type URLs or search; shows padlock (HTTPS) and site info |
| Tabs | Many pages in one window; Ctrl + T new, Ctrl + W close, Ctrl + Shift + T reopen closed |
| Back / Forward / Reload / Home | Navigation; Alt + ← / → ; F5 reload, Ctrl + F5 hard reload |
| Bookmarks / Favourites | Saved links (Ctrl + D); bookmarks bar (Ctrl + Shift + B) |
| History | Pages visited (Ctrl + H); Downloads (Ctrl + J) |
| Extensions / Add-ons | Small programs: ad-blockers, password managers, Grammarly |
| Settings | Default search engine, privacy, passwords, autofill, themes |
| Developer Tools (F12 / Ctrl + Shift + I) | Inspect HTML/CSS, Console, Network, Performance — every web developer's workshop |
| Rendering engine | Blink (Chrome, Edge, Opera, Brave), Gecko (Firefox), WebKit (Safari) |
| JavaScript engine | V8, SpiderMonkey, JavaScriptCore |
| Cache & cookies | Cache stores files for speed; cookies store small data (login session, preferences); local storage holds more |
| Incognito / Private window | Ctrl + Shift + N (Chrome/Edge) / Ctrl + Shift + P (Firefox): no local history/cookies saved — but your ISP, school and the website can still see you |
Browser shortcuts
| Shortcut | Action |
|---|---|
| Ctrl+T/W/N | New tab / close tab / new window |
| Ctrl+Shift+T | Reopen closed tab |
| Ctrl+Tab/Ctrl+Shift+Tab | Next / previous tab |
| Ctrl + 1 … 8 / Ctrl + 9 | Go to tab n / last tab |
| Ctrl+L or F6 or Alt+D | Focus address bar |
| Ctrl+Enter | Add www. and .com |
| Ctrl+D | Bookmark page |
| Ctrl+H/J | History / Downloads |
| Ctrl+F | Find on page |
| Ctrl+P | Print / Save as PDF |
| Ctrl++/−/0 | Zoom in / out / reset |
| F11 | Full screen |
| F5/Ctrl+F5 | Reload / reload ignoring cache |
| Esc | Stop loading |
| Space/Shift+Space | Scroll page down / up |
| Home/End | Top / bottom of page |
| Ctrl+U | View page source |
| F12 | Developer tools |
| Ctrl+Shift+Delete | Clear browsing data |
| Ctrl+Shift+N/P | Incognito (Chrome, Edge) / Private (Firefox) |
| Alt+Home | Home page |
| Ctrl+click | Open link in new tab |
Internet essentials
| Term | Meaning | Hindi |
|---|---|---|
| Internet | Global network of networks (1969 ARPANET → 1983 TCP/IP → 1991 WWW). India got internet on 15 Aug 1995 (VSNL) | अंतरजाल |
| WWW | The web pages that live on the internet — one service among many (e-mail, FTP, video calls are others) | विश्वव्यापी जाल |
| ISP | Internet Service Provider — Jio, Airtel, BSNL, Vi | इंटरनेट सेवा प्रदाता |
| IP address | Unique number of a device: IPv4 (192.168.1.1, 4.3 billion) and IPv6 (2001:db8::1, 340 undecillion) | आईपी पता |
| DNS | Domain Name System — names → IP addresses; Google DNS 8.8.8.8, Cloudflare 1.1.1.1 | डोमेन नाम प्रणाली |
| Domain & TLD | codekilla.com → TLD .com; .in (India), .org, .edu, .gov, .ai | डोमेन |
| HTTP / HTTPS | HyperText Transfer Protocol (secure); status codes 200, 301, 404, 500 | — |
| Bandwidth & speed | Measured in Mbps (megabits/s); 100 Mbps ≈ 12.5 MB/s download. 1 byte = 8 bits | बैंडविड्थ |
| Wi-Fi / Router / Modem | Modem connects to ISP; router shares it; Wi-Fi is wireless LAN (2.4 GHz, 5 GHz, 6 GHz) | — |
| Cloud | Servers you rent over the internet — Google Drive, iCloud, AWS, Azure | क्लाउड |
| Search engine | Google (1998, 90% share), Bing, DuckDuckGo, Yahoo; AI search: Perplexity, ChatGPT search | खोज इंजन |
| Electronic mail — Gmail (2004), Outlook; protocols SMTP (send), IMAP/POP3 (receive) | ई-पत्र / ई-मेल | |
| Cookies | Small text files a site stores in your browser (session, preferences, tracking) | कुकीज़ |
| Firewall / Antivirus / VPN | Blocks unwanted traffic / removes malware / encrypts traffic & hides IP | — |
| Phishing | Fake e-mails/sites that steal passwords and OTPs — never share OTP, check the URL | फ़िशिंग |
| Web 1.0 / 2.0 / 3.0 | Read-only pages → social & user content → decentralised, AI, blockchain | — |
Google search tricks
| Operator | Does | Example |
|---|---|---|
| "..." | Exact phrase | "first computer in India" |
| -word | Exclude | jaguar -car |
| site: | Only one site | site:codekilla.com python |
| filetype: | File type | class 10 science notes filetype:pdf |
| OR | Either | laptop OR notebook |
| * | Wildcard | "the * of computers" |
| define: | Dictionary | define:algorithm |
| .. | Number range | laptop ₹30000..₹40000 |
| intitle: / inurl: | In title / URL | intitle:resume template |
| weather / time / calculator / convert | Instant answers | 100 USD in INR |
| cache: (retired) / Wayback Machine | Old versions of a page | web.archive.org |
// Keep exploring
All chapters →