Search Engine Optimization and Web Crawler

Search engines like Google and Yahoo are most popular search engines of now days and both of these use web crawler to search the sites and blogs on the basis of keyword.Search engine optimization is the process of submitting your site to directory,link exchange with same theme of your site, social bookmarking,blog commenting and forums ,this all process is necessary to submit your site to search engines and web crawler crawl your site.It totally depends on your site what page rank it will get form the search engines and the rank of your site in search engines also depends on your keyword targeting and best search engine optimization.This is the screenshot of definition given by wikipedia.org.

Follow the rules of search engines and never spam and focus on the quality of your site.Google is very strict for web rules and the sites with illegal contents,spamming,misguiding to users and having virus in site Google ban these sites permanently and temporally.So before search engine optimization you need to make your site user and search engine friendly and the search keyword and you can search keyword here.....
https://adwords.google.com/select/KeywordToolExternal
Enter you site URL here and you will find the best keywords for your site.