Search engine optimization is a methodology of strategies, techniques and tactics used to increase the amount of visitors to a website by obtaining a high-ranking placement in the search results page of a search engine (SERP) -- including Google, Bing, Yahoo and other search engines.

Search engine optimization (SEO) is the process of affecting the visibility of a website or a web page in a search engine's unpaid results—often referred to as "natural," "organic," or "earned" results.

SEO is search engines optimization which is a technique used to provide visibility to website in different search engines and maintain online reputation.

If you want to increase your website on the search engine then you need to create backlinks, and this whole process we called SEO.

Search Engine Optimization (SEO) is a technique for increase the visibility of a website on search engine.

really?
seo is become very tough these days

SEO is search engine optimization which is use to increase the traffic on website with out paying so much money.