Internet Technologies Grade 12
How the web works under the hood — search technologies, web technologies, online applications, and how data is stored and processed online.
T3Term 3 · Internet & Web Technologies
Search Technologies
| Type | Description |
|---|---|
| Keyword search | Matches exact words in the query |
| Semantic search | Understands meaning and context behind words — interprets user intent, not just keywords |
| Mediated search | A middleman system filters results for a specific database or organisation (e.g. Google Scholar) |
| SEO | Search Engine Optimisation — techniques to make websites rank higher in search results (keywords, speed, mobile-friendly, backlinks) |
Static vs Dynamic Websites
| Static | Dynamic | |
|---|---|---|
| Content | Fixed HTML — changes only if developer edits files | Generated on demand from a database |
| Database | No | Yes |
| Examples | Simple portfolio, business info page | Online shop, social media, news sites |
| Security risk | Low | Higher (SQL injection, data breaches) |
Web Technologies
| Technology | Role | Example |
|---|---|---|
| HTML | Structure and content of web pages | Headings, paragraphs, links, images |
| CSS | Visual styling — colours, fonts, layout | Blue buttons, responsive grid |
| JavaScript | Client-side interactivity; runs in the browser | Form validation, dropdown menus, AJAX |
| PHP | Server-side scripting; processes forms, talks to databases | Login authentication, database queries |
| SQL | Query and manage database data | SELECT user data, INSERT orders |
| XML | Structured data exchange between systems | Product data feeds between websites |
| RSS | An XML-based feed format that lets users subscribe to a site and automatically receive new content as it is published | News headlines, blog posts, new podcast episodes |
Storing Data Online
- Cookies — small text files stored on the user's device by a website. Remember preferences, login sessions, shopping carts.
- Online databases — data stored on remote servers. Examples: Gmail messages, your social media posts.
- Online applications — programs that run over the internet rather than being installed on your local computer; they store data, execute instructions and present output entirely through the browser or app. Examples: Google Docs, Gmail, internet banking apps.
Running Instructions
| Client-side (browser) | Server-side (web server) | |
|---|---|---|
| Language | JavaScript, AJAX | PHP, Python, Node.js |
| Purpose | Real-time page updates, validation, animations | Authentication, database access, processing |
| AJAX | Updates parts of a page without reloading | — |
The Role of Scripting Languages
A scripting language is what turns a plain, static page into a website that actually does something. Its role always splits into two halves — what happens instantly in the visitor's browser, and what happens back on the web server — and an online store is a good way to see both halves at work at once.
Client-side scripting (e.g. JavaScript)
Runs in the customer's own browser, so it can react instantly without waiting for the server. On an online store it could:
- Validate the checkout form before it is submitted — e.g. checking that a cellphone number field isn't empty or that the quantity entered is a valid positive number — so the customer sees the error immediately, without a round trip to the server.
- Update the shopping cart total the instant a customer changes a quantity, with no need to reload the page.
- Show or hide extra product information (e.g. a "Read more" description) when clicked.
Server-side scripting (e.g. PHP)
Runs on the store's web server, so it's the only place that can safely reach the database. On an online store it could:
- Check the product database to confirm an item is still in stock before allowing checkout.
- Calculate the order total and generate an order confirmation.
- Securely process the customer's login and payment details.
- Insert the new order into the database and update the stock level once payment succeeds.
HTTP vs HTTPS
| HTTP | HTTPS | |
|---|---|---|
| Encryption | None — data sent in plain text | SSL/TLS encryption |
| Padlock | No padlock in browser | Padlock icon shown |
| Use | Non-sensitive public pages | Login, banking, shopping — any sensitive data |