Networking & Internet
URI
Definition
A Uniform Resource Identifier (URI) is a unique sequence of characters that identifies a logical or physical resource used by web technologies. URIs may be used to identify anything, including real-world objects, such as people and places, concepts, or information resources such as web pages and books.
Why It Matters
URIs provide a universal, extensible way to identify resources. They are the foundation of semantic web and linked data technologies.
Contextual Example
`https://example.com/page.html` is both a URL and a URI. An ISBN number like `urn:isbn:0-486-27557-4` is a URI, but not a URL, because it identifies a book but doesn't specify how to locate it.
Common Misunderstandings
- A URL (Uniform Resource Locator) is a specific type of URI that also specifies how to access the resource (e.g., via HTTP). All URLs are URIs, but not all URIs are URLs.
- URN (Uniform Resource Name) is another type of URI that aims to provide a persistent, location-independent identifier.