What is SEO?
When a person searches for something in the popular search engines usually only the first few results would be visited, so everybody wants to get their site there. SEO is the way to achieve this.
In other words, SEO or Search Engine Optimization is the process of improving the amount of traffic to a web site or blog from search engines. It is a marketing strategy to increase site relevance.
Search Engine Optimization can be both on-page and off-page. On-page is the optimization of the web site code and text. Off-page optimization is achieved through actions.
Web Crawlers/Spiders are programs, used to browse the web, collect and index information. What is indexed by Search Engines Crawlers can be changed through robots.txt file.
PageRank – system used by Google to represent the position of the page in their search results.
SERP – is an abbreviation for Search engine results page.
Most used search engines are Google, Yahoo and Live Search(formerly known as MSN). List of all search engines can be found on Wikipedia.
Search Engine Optimization results are not predictable. Most of the time they lead to an expected results but sometimes the most optimized site gets less traffic than other with no optimization or even with no content.