Web crawler,how it works ?

"when we uploading to a site, could the search engine found it?"

as we know, every website have two things basically :

1.Domain Name (ex : blablabla.com)
2.IP address (ex: 172.16.16.1)
The simple do by Web Crawler is searching the IP address side. So, web crawler system will start searching from the the smallest to biggest IP (ex :start from 1.1.1.1, 1.1.1.2, 1.1.1.3, so on and so on)

The "cooler" web crawler will more be awesome because not only searching the IP, but domain name too. For this process, the web crawler will read the database of DNS (Domain Name Server) and start searching from beginning till the end (ex: start from a.com, b.com, and c.com, so on untill the domain name ended)

The "coolest" web crawler not only doing two process above, it could searching the URL link from a website. So, example the web crawler visiting to "x.com", in the "x.com" have some links like "blablabla.com", the web crawler will checking the links there, include "blablabla.com" it. Later, if in the "blablabla.com" have some links to, he will checking it too. This activity doing to rank the place of a site on search engine.

If we uploading site for moment ago, of course searh engine could find it directly (by two methods above). But it will required a long time, not that day. to help "introduce" our site, we can doing some registering or introducing to search engine or "submit site" there in every web crawler, like Yahoo at : http://search.yahoo.com/info/submit.html

source : http://id.answers.yahoo.com/question/index;_ylt=An7Oj3ZZObTN0KbuPGJn_xmhRAx.;_ylv=3?qid=20080814230429AAqmjc5&show=7#profile-info-Q8yiiC54aa