The Internet is the global network of interconnected computer networks that communicate using the TCP/IP protocol suite. The World Wide Web (WWW) is a system of interlinked hypertext documents, called web pages, that is accessed over the Internet using browsers. Although the words are often used interchangeably, the Internet is the infrastructure and the Web is one of the services that runs on it, alongside email, file transfer, and messaging.
A web page is written in a markup language called HTML, styled with CSS, and stored on a web server that delivers it to a browser on request. Every resource on the Web has an address, the URL, and every machine has an identity, the IP address or domain name. Understanding this vocabulary, along with the request-response cycle between browsers and servers, forms the core of this chapter.
The syllabus expects students to know the structure of an HTML document, the most common tags, how CSS is applied, the purpose of XML, and the everyday terminology of the Web such as ISP, hyperlink, search engine, web hosting, and domain names. We will cover each of these topics, with small HTML and XML examples, so that the practical aspects of web design and the conceptual questions about the Internet are both fully prepared.
Every device connected to the Internet has a unique numeric address called an IP address, such as 192.168.1.1 for IPv4. Because numbers are hard for humans to remember, domain names like www.example.com are used instead. The Domain Name System (DNS) translates domain names into their corresponding IP addresses, so that typing a name in a browser reaches the correct server.
A URL (Uniform Resource Locator) identifies a specific resource. A typical URL has the form:
https://www.example.com:443/path/page.html?name=value
https specifies the rules used to fetch the resource.www.example.com names the server.443 is the port number, often omitted because defaults are assumed./path/page.html identifies the specific file on the server.?name=value passes parameters to the server.HTTP (Hypertext Transfer Protocol) is the request-response protocol between a browser and a web server. The browser sends a request and the server responds with the requested resource or an error code. HTTPS is the secure version of HTTP; it encrypts the data using SSL/TLS, protecting sensitive information such as passwords and payment details during transmission. Standard status codes include 200 for a successful response and 404 for a resource that cannot be found.
HTML (Hypertext Markup Language) describes the structure of a web page using tags enclosed in angle brackets. A basic document looks like this:
<!DOCTYPE html>
<html>
<head>
<title>My First Page</title>
</head>
<body>
<h1>Welcome</h1>
<p>This is a paragraph.</p>
<a href="https://example.com">Click here</a>
</body>
</html>
<!DOCTYPE html> declares the document type.<html> is the root element.<head> holds metadata and the page title.<body> holds the visible content.<h1> to <h6> are headings, with <h1> the largest.<p> creates a paragraph.<a href="..."> creates a hyperlink.<img src="..."> embeds an image, <ul> and <ol> create unordered and ordered lists, and <table> creates a table.Tags can have attributes that add information. The href attribute of the anchor tag gives the link destination, the src attribute of the image tag gives the image location, and width, height, border, and align control presentation details. The syntax is always attribute="value" inside the opening tag.
<ul>
<li>Maths</li>
<li>Science</li>
</ul>
<ol>
<li>First step</li>
<li>Second step</li>
</ol>
<ul> produces bulleted lists and <ol> produces numbered lists; each item is wrapped in <li>.
<table border="1">
<tr>
<th>Name</th>
<th>Marks</th>
</tr>
<tr>
<td>Ravi</td>
<td>88</td>
</tr>
</table>
<table> defines the table, <tr> a row, <th> a header cell, and <td> a data cell.
CSS (Cascading Style Sheets) controls the presentation of HTML elements, separating content from design. Styles can be applied in three ways: inline with the style attribute, embedded in a <style> tag inside <head>, or externally in a separate .css file linked with <link>.
<style>
p { color: blue; font-size: 14px; }
h1 { text-align: center; }
</style>
A CSS rule has a selector (p, h1) and a declaration block containing properties and values. This separation means the same HTML content can be restyled without changing the markup.
XML (Extensible Markup Language) is a markup language designed for storing and transporting data. Unlike HTML, which uses a fixed set of tags, XML lets the author define custom tags, and XML is both machine-readable and human-readable.
<student>
<name>Ravi</name>
<roll>101</roll>
<marks>88</marks>
</student>
XML documents must be well-formed: every opening tag must have a matching closing tag, tags must be properly nested, and attribute values must be quoted. XML is widely used for data exchange between different systems, for example in feeds and configuration files.
Web hosting is the service of storing web pages on a server so they are accessible over the Internet. Hosting can be free or paid, and can be shared, dedicated, or cloud based. To publish a site, the files are uploaded to the server using FTP, and the site becomes available at its domain name once the DNS records point to the hosting server.
| Tag | Purpose |
|---|---|
<html> |
Root element of the page |
<head> |
Metadata and title |
<body> |
Visible content |
<h1> to <h6> |
Headings of decreasing size |
<p> |
Paragraph |
<a> |
Hyperlink |
<img> |
Image |
<ul> / <ol> |
Unordered / ordered list |
<li> |
List item |
<table> |
Table |
<tr>, <th>, <td> |
Row, header cell, data cell |
| Term | Meaning |
|---|---|
| URL | Address of a resource |
| IP Address | Numeric identity of a device |
| DNS | Translates domain names to IP addresses |
| HTTP | Protocol for web requests |
| HTTPS | Secure version of HTTP |
| ISP | Company providing Internet access |
| Web Server | Stores and delivers web pages |
| Browser | Software to view web pages |
</p> or </body>, which breaks the page structure.href="page.html" outside the opening <a> tag, since attributes belong inside the tag.<ul> (bullets) with <ol> (numbers), and <th> (header cell) with <td> (data cell).The Internet and the Web connect the world's information through a clear system of protocols, addresses, and markup. The Internet provides the global TCP/IP infrastructure, DNS translates human-readable domain names into numeric IP addresses, and browsers and web servers exchange documents over HTTP or HTTPS using a request-response cycle. Web pages are structured with HTML tags, styled with CSS, and portable data is described with XML. Understanding this stack, from the URL in the address bar down to the server that stores the files, is essential both for the theory examination and for the practical skill of creating and publishing a web page.