HTML（超文本标记语言）、CSS（层叠样式表）和JavaScript是Web开发的三大核心技术，它们各自承担不同的职责，共同协作来创建动态的、互动的网页。下面是对这三个技术的简要介绍：
2. CSS： 作用：CSS用于设置网页的样式和布局。它使得开发者可以独立于HTML内容来控制网页的外观。 选择器：CSS使用选择器来指定哪些HTML元素应该应用样式规则。选择器可以是元素名、类名、ID或其他更复杂的选择器。 属性：CSS属性定义了样式规则，如字体、颜色、边距、布局等。属性值可以是预定义的值、颜色代码、长度单位等。
3. JavaScript： 作用：JavaScript是一种脚本语言，它允许开发者创建动态内容和交互性。它可以响应用户的操作，修改HTML和CSS，甚至与服务器进行交互。 事件：JavaScript通过监听事件（如点击、滚动、键盘输入等）来触发代码执行。 函数：JavaScript代码通常包含函数，这些函数可以封装可重用的代码块，使得代码更加模块化和易于管理。
这三个技术通常一起使用，以创建功能丰富、外观精美的网页。例如，HTML定义了一个网页的基本结构，CSS设置了它的样式，而JavaScript则提供了交互性。通过这种方式，开发者可以创建出满足各种需求的网页，从简单的静态页面到复杂的Web应用程序。
HTML, CSS, and JavaScript: The Dynamic Trinity of Web Development
Introduction
In the vast world of web development, HTML, CSS, and JavaScript are the three pillars that form the foundation of any dynamic and interactive website. Each of these technologies plays a crucial role in creating a seamless user experience. In this article, we will delve into the basics of HTML, CSS, and JavaScript, explaining their individual functions and how they work together to create a powerful web presence.
HTML: The Structure of the Web
What is HTML?
HTML, which stands for Hypertext Markup Language, is the standard markup language for creating web pages and web applications. It provides the structure and content of a webpage, defining elements such as headings, paragraphs, images, links, and more.
Basic HTML Structure
Every HTML document starts with a `` declaration, followed by the opening `` tag. Inside the `` tag, there are two main sections: the `` and the ``.
- The `` section contains meta-information about the document, such as its title, links to CSS files, and other metadata.
- The `` section contains the actual content of the webpage, including text, images, links, and other elements.
Example of a Basic HTML Document
```html
