CSS cascading order - author vs user [duplicate]

Question

In ascending order of precedence:

1. user agent declarations
2. user normal declarations
3. author normal declarations
4. author important declarations
5. user important declarations

CSS spec defines author and user as:

Author. The author specifies style sheets for a source document according to the conventions of the document language. For instance, in HTML, style sheets may be included in the document or linked externally.

User: The user may be able to specify style information for a particular document. For example, the user may specify a file that contains a style sheet or the user agent may provide an interface that generates a user style sheet (or behaves as if it did).

.. but its still not clear to me if I, the developer of the website/app, is the user or the author? Whats the difference between the two?

Answer 1

Author

The developer of the original CSS code for that application. Let's say the Front-end developer of StackOverflow website is the Author here.

Any changes made on Author code will effect the application style for everyone.

User

You want to have custom style for the pages that you view. Eg: If you need to change the background color of Stackoverflow website, you can use Stylish extension to append your custom style rules. Now you are the user here.

You can filter the user styles in the Style Side Panel which shows the system applied styles as well as user defined custom CSS.

Any changes made on this code will affect only your browser.