In REST architecture, how is each resource identified?

• A. By IP address
• B. By URIs
• C. By URL parameters
• D. By HTTP methods

Answer: (B)

In REST architecture, each resource is identified using URIs (Uniform Resource Identifiers). This method allows for a standardized way to uniquely locate and interact with resources on the web. Each resource, which can be anything from a user's data to a repository of images, has a distinct URI that serves as its address, ensuring that clients can reliably access and manipulate these resources.

Using URIs is foundational to REST because it maintains a separation of concerns; resources are identified independently of the operations that can be performed on them. This is critical in ensuring scalability and flexibility within a RESTful service, as applications can evolve independently of one another as long as they adhere to the defined resource structure.

The other options do not provide the same level of specificity in identifying resources. For example, an IP address, while it can point to a server hosting resources, does not necessarily identify the individual resources themselves. URL parameters might be used for filtering or modifying requests, and HTTP methods (GET, POST, PUT, DELETE) define actions rather than identify resources. Therefore, URIs stand out as the authoritative method of identifying resources in REST architecture.