!important property

HTML

<div class="class1">
  <p class="p1">class1 p1</p>
  <p class="p1">class1 p1</p>
</div>

<div class="class2">
  <p class="p2">class2 p2</p>
  <p class="p2">class2 p2 </p>
</div>

CSS

/* notice the !important property preventing the texts from being blue */
.class1 {
  color: red !important; 
}

.class1 {
  color: blue;
}

.class2 {
  color: green;
}