Seo tutorial

Architecture of Search Engine

Crawler--- automatically follows all of the links on each web page.

Spider---- downloads web pages like a browser

Indexer--- analyzes web pages downloadeds by the Spider and the Crawler.

Database--- a storage for downloaded and processed pages.

Results engine--- extracts search results from the database.

Web server---- a server that is responsible for interaction between the user and other search engine components.
                    The position of a site in the SEO can be divided in to ----

1. Internal ranking in seo

2. External ranking in seo