Search Engine Optimization comprises of various aspects and tools that is being used in the process. Search Engine Optimization is a part of search engine marketing which deals in the promotion of web sites on various search engines. SEO is that part of search engine marketing which is also called as organic listings in search engines.

There are two types of search engine listings:
1) Sponsored Listing: Sponsored listings refer to that list of advertisements for which we have paid search engines to rank the web site.

2) Organic Listing: Organic listings refer to the list of web sites which appear in SERP’s (search engine result pages).For organic listings nothing is paid to the search engines. It is based on the on-page and off-page optimization done for the website.