- External style sheet
An external style sheet is a separate, text-only document (with .css suffix) that contains a number of style rules. That document is then linked to the HTML document through the <link> element, or imported into another CSS document through the @import rule. External style sheets can be applied to multiple documents.
- Embedded style sheet
It is placed in an HTML document via the <style> element (in the <head> of the document), and the styles only apply to that document.
- Inline styles
We can apply properties and values to a single element by using the style attribute in the element itself:
<h1 style="color: red; margin-top: 2em">Introduction</h1>The styling will only apply to the element.