The World Wide Web is the most-used service of the Internet — the web of pages you browse every day. This chapter covers how the web is addressed and served, how pages are built, and how to stay safe doing business online.
1Core web concepts
| Term | Meaning |
|---|---|
| WWW | World Wide Web — the global collection of linked web pages and resources, accessed over the Internet. |
| URL | Uniform Resource Locator — the full address of a web resource, e.g. https://vidaara.org/courses. |
| DNS | Domain Name System — the web's 'phone book' that translates a domain name (vidaara.org) into the server's IP address. |
| Web hosting | Renting space on a server to store a website's files so they're available on the Internet. |
When you type a URL, DNS finds the server's IP address, your browser requests the page over HTTP/HTTPS, and the hosting server sends it back. You met DNS in Class 11's 'How the Web Works' — same idea, more formally here.
Key points
- WWW = the global web of linked pages; URL = the full address of a web resource.
- DNS translates a domain name into the server's IP address (the web's phone book).
- Web hosting = server space that stores a website's files so they're reachable online.
2Static vs dynamic; client vs server scripting
| Static website | Dynamic website | |
|---|---|---|
| Content | Fixed — same for every visitor | Generated on the fly — can differ per user/time |
| Built with | Mainly HTML & CSS | HTML/CSS + a server program + often a database |
| Example | A simple info page | Gmail, an online store, a social feed |
Client-side vs server-side scripting
- Client-side scripting runs in the browser (e.g. JavaScript) — instant interactivity like form checks and animations.
- Server-side scripting runs on the server (e.g. Python, PHP) — handles databases, logins and anything that must be done securely before sending the page.
A dynamic site usually uses both: server-side code to build the page from a database, and client-side code to make it interactive in the browser.
Key points
- Static sites have fixed content (HTML/CSS); dynamic sites generate content on the fly (server program + database).
- Client-side scripting runs in the browser (JavaScript) for interactivity.
- Server-side scripting runs on the server (Python/PHP) for databases, logins and secure work.
3E-commerce and security
E-commerce is buying and selling online. A payment gateway securely handles the transaction between the customer, the shop and the bank. Cookies are small files a site stores in your browser to remember you (login, cart, preferences).
Threats
| Threat | What it is |
|---|---|
| Virus | Malicious code that attaches to a file and spreads when run. |
| Worm | Self-replicating malware that spreads across a network on its own. |
| Trojan | Malware disguised as a useful program. |
| Phishing | Fake messages/sites that trick you into giving passwords or card details. |
Defences
- Firewall — monitors and filters network traffic, blocking unauthorised access.
- Encryption — scrambles data so only the intended recipient can read it (the 'S' and padlock in HTTPS).
- Antivirus, strong passwords, two-factor authentication, and caution with links (from Class 11's Cyber Safety).
Key points
- E-commerce = online buying/selling; a payment gateway securely processes the transaction; cookies remember you in the browser.
- Threats: virus (attaches to files), worm (self-spreads over a network), trojan (disguised), phishing (tricks you into giving secrets).
- Defences: firewall (filters traffic), encryption (scrambles data — HTTPS), antivirus, strong passwords, 2FA.
★ Practical: web know-how
Answer briefly:
- Explain what DNS does when you type vidaara.org.
- Is an online store static or dynamic? Justify your answer.
- Give one task suited to client-side scripting and one to server-side scripting.
- Name two security threats and the defence(s) that counter them.
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