SEO is a Methodaology of strategies and techiniques used to increase the website traffic and to reach higher ranking in search engine results page.
PPC is an online advertising process in this advertisers pay every time a user clicks on one of their online ads.
SEO:
1. On-page SEO
2. Off page SEO
on-page seo factors:
1. Meta tags
2. Heading tags
3. Url structure
4. Content
5. Keyword Density
6. Keyword prominance
7.Internal Links
8. Site Speed
9. Robot.txt
10.Sitemap.xml etc..
Off-page techniques:
1.Guest posting
2.Social Bookmarking
3.Forum submissions
4.Content sharing
5. answering in Q&A sites etc…