Chaining is best viewed in the HTML…
<p class="note italic"></p>
When testing in your browser, toss in the variations…
<div class="note italic"></div>
Each of these have different selector options.
The chain is more specific than otherwise. It means A AND B whether chained to a type or not. With a type it is P AND A AND B.
It is important to note that a chain is only a chain if there is no whitespace separating the selectors.
p .note .italic
is NOT the same as,
by any stretch. Completely different. The latter is a single selector that targets a single element (or group of elements that match) whereas the former is targeting CHILD elements.
class italic that is child of class note that is child of P