The difference between a URL and a URI

Summarized as follows:

1. Abbreviations:
URI (Uniform Resource Identifier) uniform Resource identifier;
URL (Uniform Resource location) Uniform Resource Locator (or Uniform Resource Locator);
URN (Uniform Resource Name) uniform Resource naming.

Comparison of 2.URI and URLs

A.
A URI is a relatively broad concept, a URL is a URI, a subset of the URI naming mechanism, it can be said that the URI is abstract, and specifically to use the URL to locate the resource.

B.
Every resource on the web, such as pictures, documents, videos, etc., is located by Uri, where the so-called positioning refers to the specific path on the server that the resources on the web are stored on the servers relative to the host server.

C.
A URL is a string on the Internet that describes an information resource file, used on client programs and servers to locate the information needed by the client to connect to the server, not only locating the information resource, but also defining how to find it.

3. My understanding
URI is a resource positioning mechanism, it is relatively general positioning of resources, not limited to the client and server,

And the URL to locate all the resources on the Internet, as long as the resources on the Internet, there is a unique URL.

4, URI is a Uniform resource identifier, is a string used to identify an Internet resource name. This type of identification allows users to interact with any resource, including local and internet, through a specific protocol.

The URI is defined by a scheme that includes a determination of syntax and related protocols. Consists of three components: the naming mechanism for accessing the resource, the host name that holds the resource, and the name of the resource itself, represented by the path.
For example, the URL of the file, the server mode with file, followed by the host IP address, file access path (that is, directory) and filename and other information. Directories and file names can sometimes be omitted, but the "/" symbol cannot be omitted.
Example: File://a:1234/b/c/d.txt represents the acquisition of resources using the FTP protocol, the resource target is a host of the 1234 port of the B directory under the C directory under the D.txt.
5, the URL is a unified resource positioning, is to be available from the Internet, the location of resources and access methods of a concise expression, the Internet is the address of the standard resources.

Each file on the Internet has a unique URL that contains information that indicates the location of the file and how the browser should handle it.

The difference between a URL and a URI