What are the difference between URL, URI, and URN?

Understanding the differences between URL, URI, and URN can be crucial in web development and networking. Let's break down these concepts:

URL (Uniform Resource Locator):

• Definition: A URL is a specific type of URI that not only identifies a resource on the internet but also provides a method to locate it by describing its primary access mechanism, usually its network location.
• Components: It typically includes a protocol (such as HTTP, HTTPS, FTP), domain name, and path, optionally followed by query parameters or a fragment identifier.
• Example: https://www.example.com/path?query=term#section
• Key Characteristics:
  • Specifies how the resource can be accessed (protocol).
  • Includes the location of the resource (like a web address).

URI (Uniform Resource Identifier):

• Definition: A URI is a generic term used to identify a resource either by location, name, or both. It serves as a universal identifier for resources on the internet.
• Scope: All URLs and URNs are URIs, but not all URIs are URLs or URNs.
• Example: A URL https://www.example.com is also a URI, and a URN like urn:isbn:0451450523 (identifying a book by its ISBN) is also a URI.
• Key Characteristics:
  • A more general concept than both URL and URN.
  • It can be either a locator (URL), a name (URN), or both.