What's behind a URL?

Question

What are the parts that make up a url? I'm kinda confused about how a "url" works. I understand it's a "path" to a location on the internet, but what do they mean?

For example: serverfault.com

serverfault is in relation I assume the name of the page you're looking for, but what does the .com part really represent? In short, I know it implies it's a commercial site, but what does the .xxx part represent? Is it suppose to represent a subdomain or something?

How can you explain a URL easy enough for most people to understand?

Also, what's "www" used for? Ex if you enter "www.serverfault.com", it'll do the exact same thing that typing "serverfault.com" does, so is it only a placeholder? — yuritsuki, Apr 16 '13 at 03:14

score 6 · Answer 1 · edited Apr 16 '13 at 14:11

Let's break this example down briefly: http://www.serverfault.com/questions.

http:// - the protocol used (HTTP in this case)
www - the third level domain, sometimes used as a hostname. Also frequently called a subdomain.
.serverfault - the second level domain, which is registered with a domain registrar
.com - the top level domain
. - the root domain. This is implied, although not written in standard URL notation. Thus the full domain name is actually "serverfault.com."
/questions/ - the actual directory or page requested at serverfault.com.

Each subsequent level after the root (root-> TLD -> SLD -> Subdomain/host) provides increasing specificity, in theory.

The structure of web page URLs is also closely linked with the way DNS operates.

Wikipedia has more complete information.

What's behind a URL?

1 Answers1