Search Engine Optimization or Search Engine Optimization is process of improving the visibility of a website or, a web page in search engines.

1.Online Search Engine Optimization.
2.Offline Search Engine Optimization.
In the online Search Engine Optimization we links our site in the coding of a website, And in Offline Search Engine Optimization we work separately from the web site.
There are basic concept which are used in offline:
Directory Submission
Blog Submission
Article Submission
Forum Posting
Press Relies etc.