What is the World Wide Web?
Typing a search word and clicking a link feels effortless, but it relies on a simple idea: hyperlinked documents running on top of the Internet. Here is a lightweight tour of how the Web is layered and what to watch for when it misbehaves.
So, what is the WWW? ๐
The Web is a system of documents connected by hyperlinks. It rides on the Internet and ships information using HTTP and HTML.
Web vs. Internet
- Internet: the physical and logical network (IP, routers, fiber) that moves packets.
- WWW: the delivery rules (HTTP/HTTPS) and document format (HTML) that sit on that network. Mail, FTP, SSH, and other protocols coexist on the Internet but are not part of the Web.
Three ingredients of the Web
- URL/URI: the address that says where a resource lives.
- HTTP: the delivery protocol that carries the request to that address.
- HTML + links: the human-friendly document that points you to the next place.
Looking at a URL ๐
The address bar exposes clues about where you are going and whether it is safe.
URL anatomy
| Part | Example | Meaning |
|---|---|---|
| Scheme | https:// | How to talk to the server. HTTP/HTTPS dominate the Web. |
| Host | www.example.com | The name DNS resolves. "www" is just a subdomain; it is optional. |
| Path | /docs/www | Location on the server. Could be static or dynamically generated. |
| Query | ?q=web | Extra parameters; search and filters love this. |
| Fragment | #what-is | In-page anchor. Handled by the browser, not sent to the server. |
What happens when you click a link
- The browser resolves the host name to an IP via DNS (using cache when possible).
- If HTTPS, it negotiates TLS to set up an encrypted channel and checks the certificate.
- It sends an HTTP request (GET/POST and headers).
- The server replies, then the browser fetches HTML/CSS/JS/images as needed to render the page.
HTTP basics ๐จ
HTTP is a simple request-response protocol. It is stateless, so every request carries the context it needs in headers.
Requests and responses
- Methods: GET for retrieval, POST for submit/create, PUT/PATCH/DELETE for updating APIs.
- Headers: User-Agent, Accept, Cookie, and cache directives tell the server how to respond.
- Responses: status codes (200, 404, 503, etc.) plus headers and a body.
Remembering state
- Cookies: tiny pieces of data stored by the browser and sent back, often holding a session ID.
- Caching: Cache-Control and ETag allow clients to reuse resources to save time and bandwidth.
- Redirects: 301/302/307 steer the browser to another URL (HTTPS enforcement, www/non-www alignment).
Common status codes
| Code | Meaning |
|---|---|
| 200 OK | All good. |
| 301/302 | Moved elsewhere. Used for canonical URLs or HTTPS redirects. |
| 304 | Not modified; you can keep your cached copy. |
| 400/403/404 | Bad request / forbidden / not found. |
| 500/503 | Server-side issue such as errors or maintenance. |
The Web today ๐
Browsing feels effortless because the ecosystem has moved to safer, faster defaults. A few trends are worth noting.
HTTPS by default
- Expired certificates trigger scary warnings. Automated renewal (e.g., Let's Encrypt + cron) is essential.
- HTTP/2 and HTTP/3 assume HTTPS and speed things up with multiplexing and header compression.
- HSTS and redirects commonly force HTTP traffic onto HTTPS.
Web beyond the browser
- Mobile apps and IoT devices call HTTP(S) APIs to fetch or update data.
- Web APIs that return JSON or XML (not HTML) still follow the same URL design and caching principles.
Privacy shifts
- Third-party cookies are being restricted, pushing analytics and ads toward first-party or server-side approaches.
- Tracking protections may strip referrers or user agent details, so analytics configuration matters.
Quick tips ๐ก
A few reminders that help when designing links or debugging odd behavior.
When things break
- Clear cache and cookies to rule out stale redirects or sessions.
- DNS changes take time to propagate; use dig to see what you actually resolve.
- Check certificate validity, SAN entries, and intermediates; expirations cause most browser warnings.
- Watch for same-origin policy or CORS blocking requests across domains or subdomains.
Link design
- Aim for stable permalinks; use 301 redirects when moving content.
- Fragments (#id) enable deep links into long pages and make sharing easier.
- Tune metadata like OGP so previews look good on social or search results.