Which one is better-ppc or Seo?

SEO is better as it helps to rank keywords higher in search engines. PPC only helps to promote your keywords to gain more traffic through successful campaigns.
Organic search engine traffic can provide an improved ROI over traditional forms of paid media and certainly improve upon PPC. Cost. While SEO is neither cheap nor easy, it will generally be more cost-effective than all other marketing tactics for delivering brand awareness and relevant traffic to your website