Secondary source is more like say you were at home and your friends tell you about a Party in the phone he's giving you information since it weren't there
<h2><em>So</em><em> </em><em>That</em><em> </em><em>-</em><em> </em><em>I</em><em>t</em><em> </em><em>tells us for what purpose something is done</em></h2>