SEO is a technique which helps the search engine find and rank your site higher than other million of sites in response to a search query thus SEO helps driving more traffic from Search engine. SEO has 2 types:

1. On-site SEO: The technique which is used to make a change on the page for the purpose of ranking that page is called "On-site SEO".

2. Off-site SEO: Off-site refers to inbound linking from other website pages to your website pages.