Answer 1

Well castading is order of what styling will be displayed.
If you have ex. h1 {color:red;}
And after that in css you put h1 {color:blue} your h1 will be blue because of cascading. There is also rule for inline, internal and of couse external css.
To learn more you can read on w3school.

Also if you make more css files with same atributes cascading is very important. Ex. main css and custom css for each page of web site.

Answer 2

To explain better first answer. Browser style is some default style of browser. Ex to have already some padding and margin around element, User is users custom styles and it overide browser one. Author is what you make like designer of web sites.
No worry you will understand all if you practice. Most designer use now some reseting style, where we get rid of default style in browser to user see site how it need to be.

Answer 3

"Cascading" means that styles can fall (or cascade) from one style sheet to another, enabling multiple style sheets to be used on one HTML document.

Even the simplest HTML document may have three or more style sheets associated with it including:

The browser's style sheetThe user's style sheetThe author's style sheet

Source:

http://css.maxdesign.com.au/selectutorial/advanced_cascade.htm

Thanks

Answer 4

See
CSS stands for Cascading Style Sheets.

- Cascading refers to the way CSS applies one style on top of another.

- Style Sheets control the look and feel of web documents.

You can learn CSS from this course :

https://www.sololearn.com/Course/CSS/?ref=app

Thanks

Answer 5

Cascading is used for style the HTML tag