In our CSS, why select .contact-info li.phone a - seems the same thing happens if you select .phone a?

(A) If the element you want to style is unique you can just use it's id or class 
or even if it's attribute has a unique value can be used as well.  For  example:
#unique {
  color: blue;
}

img[class="dogs"] {
  color: gray;
}


(B) Sometimes if you want to select just one element you will need to be very 
specific about it and take the longer path.  Let's say you have three ul lists and 
you just want to get to the second list:
<ul>
  <li>Hi</li>
  <li><span id="unique">Take Me!</span></li>
</ul>
ul li #unique {
  color: green;
}


(C) If you want to style two or more elements the same, then you just need to 
give them the same class name and just use that class name to get to them.  In 
other words a very short path:
.className {
  color: orange;
}