# XML, HTML, and CSS

Source: https://wisconsin.twango.dev/sp25-cs400/topics/xml-html-css

# XML, HTML, and CSS

## XML (eXtensible Markup Language)

XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is designed to be self-descriptive and extensible, allowing users to define their own tags and structure.

> [!example] 
>
> ```xml
> <node data="4">
>     <node data="2">
>         <node data="1"></node>
>         <node data="3"></node>
>     </node>
>     <node data="6">
>         <node data="5"></node>
>         <node data="7"></node>
>     </node>
> </node>
> ```
>
## HTML (HyperText Markup Language)

HTML is the standard markup language for creating web pages and web applications. It defines the structure and content of a web page using a system of tags and attributes.

[HTML Element Reference](https://www.w3schools.com/tags/default.asp)

## CSS (Cascading Style Sheets)

CSS is a style sheet language used for describing the presentation of a document written in HTML or XML. It allows web developers to control the layout, appearance, and style of multiple web pages all at once.

It is specified as a key-value pair, where the key is the property and the value is the value of that property.

```css
body {
    background-color: lightblue;
}
```

### Selectors

Selectors are used to select the elements you want to style. There are several types of selectors:

- `element-name`: Selects all elements with the specified name.
- `.class-name`: Selects all elements with the specified class name.
- `#id-name`: Selects the element with the specified id.

[CSS Selectors Reference](https://www.w3schools.com/cssref/css_selectors.asp)

## Connections

- [[sp25-cs400/topics/index|Topic index]]

Obvious technical and formatting errors repaired.