Spider :- A browser-like program that comes to our site and downloads our web pages.
Crawler :– Crawler is a search engine program, who automatically follows all on each web page.
Indexer :– Indexer is a search engine program, who analyzes our web pages which were downloaded
by search engine spider & crawler.
Database :– Search Engine use Database for storage all data of web sites downloaded pages
at the processing of crawling and indexing.
Web server :– Web server is responsible for interaction between the user and search engine components.
