The Internet is a giant network of networks connecting computers worldwide. The World Wide Web is the most popular service running on it. This chapter builds the vocabulary you'll use for the rest of the course — and that powers everything you do online, from a Google search to sending an email.
1The World Wide Web — servers and clients
The World Wide Web (WWW) is a vast collection of linked documents (web pages) stored on computers across the world, accessed over the Internet. People often say "the web" and "the Internet" as if they mean the same thing, but they don't:
| Term | What it is |
|---|---|
| Internet | The worldwide network of connected computers (the roads) |
| WWW | One service that runs on the Internet — linked web pages (the traffic on the roads) |
Servers and clients
The web works on a client–server model:
- A web server is a powerful computer that stores websites and sends web pages when they are requested. It stays on all the time.
- A web client is the program that requests and displays pages — usually a web browser on your phone or computer.
- The Internet is the global network; the WWW is a service of linked web pages running on it.
- A web server stores websites and serves pages on request; it runs continuously.
- A web client (your browser) requests pages from servers and displays them — the client–server model.
2Websites, web pages and web browsers
A web page is a single document on the web (written in HTML). A website is a collection of related web pages grouped under one name — for example, the Vidaara website has a home page, a courses page, a blog, and many more, all linked together.
- The first page you see is usually the home page.
- Pages are joined by hyperlinks (clickable text or images) that take you from one page to another.
Web browsers
A web browser is the software that fetches web pages from servers and displays them for you. Common browsers:
| Browser | Made by |
|---|---|
| Google Chrome | |
| Mozilla Firefox | Mozilla |
| Microsoft Edge | Microsoft |
| Safari | Apple |
- A web page is one HTML document; a website is a group of related pages under one name.
- The home page is the main/first page; hyperlinks connect pages together.
- A web browser requests, interprets and renders web pages (Chrome, Firefox, Edge, Safari).
3Blogs, newsgroups, URLs and email addresses
Blogs and newsgroups are two ways people share and discuss content online:
- A blog (from "web log") is a website where an author posts entries (articles) regularly, shown newest-first; readers can usually comment.
- A newsgroup is an online discussion forum where members post messages on a topic and others reply, forming threads.
Web address (URL)
Every page has a unique address called a URL (Uniform Resource Locator). Its parts:
https://www.vidaara.org/courses/computer-science | | | protocol domain name path to the page
- Protocol — how to fetch it (https).
- Domain name — the website's address (www.vidaara.org).
- Path — which page on that site (/courses/computer-science).
Email address
An email address identifies a mailbox: username@domain — e.g. student@vidaara.org. The @ separates the user name (student) from the domain (vidaara.org) of the mail server.
- A blog is a regularly-updated personal/topic website (newest posts first); a newsgroup is a threaded discussion forum.
- A URL has three parts: protocol, domain name and path to the page.
- An email address is username@domain; the @ separates the mailbox name from the mail server's domain.
4Uploading and downloading files
Moving files between your device and a remote computer (a server) has two directions:
| Action | Direction | Example |
|---|---|---|
| Download | Remote server → your device | Saving a PDF, installing an app, watching a video |
| Upload | Your device → remote server | Posting a photo, submitting an assignment, attaching a file to email |
The speed of these transfers depends on your bandwidth (how much data the connection can carry per second, measured in Mbps).
- Downloading = copying a file FROM a remote server TO your device.
- Uploading = sending a file FROM your device TO a remote server.
- Transfer speed depends on bandwidth (data per second, in Mbps).
★ Practical: read the web around you
Using any browser:
- Open a website and identify its protocol, domain name and the path of the current page from the URL bar.
- Find a hyperlink on the home page and note which page it leads to.
- Name the browser you are using and the company that makes it.
- Give one example each of an upload and a download you have done this week.
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