2. Search engine crawl system

As we have already seen, several steps are necessary for a search engine to function properly:

• In the first phase, software crawls the Web from link to link, retrieving information from web pages;

• This information is then indexed by indexing engines, with the indexed terms enriching a regularly updated – database of words contained in – pages;

• finally, a search interface enables results to be returned to users by ranking them in order of relevance.