The introduction says &quot;Most eukaryotic genes carry protein-coding exons that are separated by non-coding introns&quot; so I think it&#x27;s safe to assume that at least one purpose is to code for proteins.<p>Beyond that, you may need to spend some time learning molecular biology to understand what even a summary like <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Exon#Function" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Exon#Function</a> means.<p>I personally don&#x27;t have that understanding enough to provide advice, but there are many freely available teaching materials, including videos like <a href="http:&#x2F;&#x2F;freevideolectures.com&#x2F;Course&#x2F;2304&#x2F;Introduction-to-Biology" rel="nofollow">http:&#x2F;&#x2F;freevideolectures.com&#x2F;Course&#x2F;2304&#x2F;Introduction-to-Bio...</a> , to help you reach your goal of understanding what an exon does, to whatever level you want to take it.