Which identifier uniquely references an internet resource and can be used in both remote and local contexts?

• A. URL
• B. IP Address
• C. Domain Name
• D. Uniform Resource Identifier (URI)

Answer: (D)

The idea being tested is that a URI is a universal identifier for a resource that works in both local and remote contexts. A URI is any string that identifies a resource using a defined syntax, and it can refer to something on the web or a local file. For remote resources you commonly see http:// or https:// URIs, which tell you how to access the resource, while for local resources you can have file:/// paths that point to files on a local machine. This flexibility makes a URI the most general and appropriate choice for uniquely identifying a resource across different contexts.

A URL is a specific type of URI that focuses on how and where to locate the resource, rather than the identity of the resource itself. A domain name points to a host, not to a specific resource. An IP address identifies a host or endpoint, not the resource by itself. A URN identifies a resource by name within a namespace, which is not as commonly used for everyday addressing.