The importance of SEO is helps your site and topics that inside it to be in the first results when looking for it in search engines such as: Google , Yahoo, Bing..etc

So that your good knowledge of SEO criteria and search engines optimization , which means more accurately  "Making your site perfectly compatible whether in  technical or whether in original content using a specific mechanism"...

all that makes it easier for search engines to make your site the first results when anyone looking for articles  exits  inside your site.