Which of the following best describes a URL?

A URL, or Uniform Resource Locator, is best described as a unique identifier for web documents. This is because a URL specifies the exact address of a resource on the internet, allowing users to access different web pages, images, videos, and other types of content directly. Each URL is unique to its resource, effectively distinguishing one document from another within the vast landscape of the web.

Although a structured model for resource locations has elements of accuracy, it doesn't capture the essence of what a URL primarily represents. A URL does provide a structured way to locate resources—using components like the protocol (such as HTTP or HTTPS), domain name, and path to the resource—but it is fundamentally about the uniqueness and identity of that resource on the web.

In contrast, a uniform method for internet communication describes protocols and standards that enable data exchange, while an encoding format for documents refers to how data is represented and processed rather than how it is located and accessed online. Thus, a URL as a unique identifier encapsulates its primary function more effectively than the other options.