SEO means the improvement of website visibility in a search engine by attracting organic traffic or earned results but PPC is a paid service by the publisher where the advertiser has to pay him on every advertisement visit by the viewer. SEO boosts search results where greater impressions attract greater traffic and you can track your results. It targets ready customers so it’s really cost effective thereby making your website more navigable. But the results will take more time to accomplish as there is a long time to reach ROI whereas PPC is simply, a cost per click mechanism. It can trigger early sales, is quite measurable through Adwords and can be steered quickly above the competition by optimization so reaching out to customers becomes really affordable. However being a bit complicated means more time and effort required. This calls for an expensive mechanism which can make people unwilling through their compulsion drive as people are ignore ad promotions heavily.
While both the techniques have some edge over other, only a wiser approach utilizing them gets rewarding appreciation.