This is not new stuff, but anyway I decided it to re-post it for others.
One of the most powerful features of CSS is the cascading. Knowing how a browser chooses and applies your styles is invaluable knowledge. Novices can find it especially confusing given that style use is influenced by the method used to include the CSS, the order of the rules, how the selectors are specified, and special declarations such as !important.
Inline styles are those defined in the HTML itself, e.g.