URI, URL, urn difference, and contact

　

Uri,url,urn

As can be seen from the above picture, there are three different concepts Uri,url,urn. The best way to discuss such a problem is to go back to the point where we have collected some information in RFC 3986:uniform Resource Identifier (URI): Generic Syntax:

"A Uniform Resource Identifier (URI) is a compact string used to indicate abstract or physical resources. ”

"A URI can be further divided into locators, names, or both." The term "Uniform Resource Locator" (URL) is a subset of URIs that, in addition to identifying a resource, provides a primary access mechanism (such as its network "location") to locate the resource. “

That's what we all know about Wikipedia, which digests this piece well and describes it more vividly:

"URIs can be divided into url,urn or one thing with locators and names characteristics at the same time. A URN acts like a person's name, and the URL is like a person's address. In other words: The urn determines the identity of the object, and the URL provides a way to find it. ”

We can get some conclusions from these descriptions:

• First, the URL is one of the URIs (see it through that graph). So someone told you that the URL is not a URI, he is wrong.
• The "Access mechanism", "network location", is of course the URL where the URI can be made. e.g. http:// or.. ftp://
• A urn is part of a unique identity and is a special name.

Let's take a look at an example, when it comes to an RfC that comes from authority:

• ftp://ftp.is.co.za/rfc/rfc1808.txt(also a URL because of the protocol)
• http://www.ietf.org/rfc/rfc2396.txt(also a URL because of the protocol)
• ldap://[2001:db8::7]/c=GB?objectClass?one(also a URL because of the protocol)
• mailto:[email protected](also a URL because of the protocol)
• news:comp.infosystems.www.servers.unix(also a URL because of the protocol)
• tel:+1-816-555-1212
• telnet://192.0.2.16:80/(also a URL because of the protocol)
• urn:oasis:names:specification:docbook:dtd:xml:4.1.2

These are all URIs, some of which are URLs. What? is the ones that provide access mechanisms.

Summarize

Here's the time to answer the question:

When we replace the Web address, is the URI and URL that more accurate?

Based on the many articles I read, including the RfC, I would like to say that URIs are more accurate.

Don't worry, I have my reasons:

The URI that we often use is not a strictly technical URL. For example: The file you need is in the files.hp.com . This is the URI, but not the url--system may have a lot of protocols and ports to make positive

The correct response.

You go http://files.hp.com and ftp://files.hp.com . May get completely different content. This situation may be more common, think of different Google domain names on different services AH.

So, with a URI, you are usually technically correct, and the URL is not necessarily.

URI, URL, urn difference, and contact