Web Pages | Computer for GCSE/IGCSE - Year 11 PDF Download

Web Pages

• When a URL is entered or a link is clicked, the browser transmits the URL to the DNS using HTTP.
• The DNS then discovers the corresponding IP addresses for the URL and forwards the IP address to the web browser.
• Subsequently, the web browser dispatches a request to the web server, seeking the web pages.
• The requested web pages are transmitted from the web server to the browser.
• The browser interprets HTML to exhibit the web pages to the user.
• During this process, any necessary security certificates are shared.
• SSL/HTTPS protocols are employed to secure the transmitted data, ensuring encryption of any sent information.

Structure & Presentation

Websites can be categorized into two main aspects: structure and presentation.

HTML Overview

• HTML is a language used for creating the structure and layout of a website.
• It is written in plain text, making it easily readable and editable.
• HTML is utilized in the content layer of a website to define the elements present.
• Comprised of a set of markup codes, HTML provides instructions on how content should be displayed.
• It instructs the browser on how to render and display the web page to the user.

Examples of HTML Usage:

• Where text is placed: HTML determines the positioning of text on a webpage.
• Margins of page: HTML controls the spacing around the content on a page.
• Line break: HTML specifies where a new line should begin in the content.
• Padding: HTML sets the space between the content and the boundaries of an element.

CSS Overview

• A language utilized for creating page formatting and presentation.
• Written in plain text for ease of understanding.
• Utilized in the presentation layer to ensure a consistent format across various web pages.

Examples of CSS Usage:

• Font size: Determines the size of text on a webpage.
• Font color: Specifies the color of the text.
• Background color: Sets the color of the webpage background.

Why are they kept separately?

• Page presentation can be modified without altering the structure, allowing for seamless updates without structural checks.
• CSS formatting documents can be reused for different websites, promoting efficiency in design implementation.
• Additional content and web pages can easily inherit existing formatting, reducing development time.
• CSS enables standardization of formatting, requiring creation only once and application across multiple webpages.
• Division of labor allows one person to focus on structure development and another on presentation, streamlining website development and updates.