URI vs URL vs URN: Understanding the Differences

This article clarifies the distinctions between URI, URL, and URN.

URI - Uniform Resource Identifier

• As the name suggests, URI stands for Uniform Resource Identifier.

• It acts as a label that names or locates a resource on the internet.

• In essence, a URI is a string of characters used to identify a resource on the internet, either by its location, name, or both.

• Analogy: Think of it as a person’s contact details, including email, phone number, and address.

• Example:

  Name: Alex Willer Address: 7081 Columbia street Woonsocket, RI

image alt: URI URL URN

URL - Uniform Resource Locator

• URL stands for Uniform Resource Locator.

• It’s a string of characters that specifically uses the address to locate a resource.

• It defines the protocol used to communicate with the resource.

• Examples of protocols used in URLs include FTP, HTTP, FILE, and MAILTO.

• Analogy: It’s one specific way to contact a person, like using their physical address.

• A URL is a type of URI.

• Example:

  Address: 7081 Columbia street Woonsocket, RI

A URL consists of at least two required components: a protocol and a domain. Optional components include the path and port.

Example: https://www.rfwireless-world.com:80/Tutorials/networking-tutorial.html

• http indicates the protocol.
• www.rfwireless-world.com indicates the domain.
• 80 indicates the port (optional).
• /Tutorials/networking-tutorial.html indicates the path (optional).

URN - Uniform Resource Name

• URN stands for Uniform Resource Name.

• It identifies a resource only by its name. No location or other contact information is provided.

• URNs define namespaces.

• Analogy: It’s like knowing a person’s name but not their address or phone number.

• Example:

  Name: Alex Willer

• A book’s ISBN (e.g., ISBN 0-486-27557-4) is designated as a URN. To access the book, you’d need its URL (location).

Summary

Both URNs and URLs are types of URIs. In short, URIs specify an address (URL), a name (URN), or both. URLs are most commonly used to identify resources on the internet.