URL sum URI

1. Abbreviation:
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.
2. Comparison of URI and URL
a.
URI is a relatively broader concept. URL is a kind of URI and a subset of URI naming mechanism. It can be said that URI is abstract, and URL is used to locate it. resource.
b. Every resource on the
web , such as pictures, documents, videos, etc., is located by URI. The so-called location here refers to the specific path of resources on the web stored on the server relative to the host server. .
c.
URL is a string used to describe the information resource file on the Internet. It is used on the client program and server to locate the information needed by the client to connect to the server. It not only locates the information resource, but also defines how to find the resource.
3. In my vernacular understanding
, URI is a resource locating mechanism. It locates resources in a more general way, not limited to clients and servers, while URL locates all resources on the Internet. As long as it is on the Internet, there are Unique URL.

URL format: The URL address format is arranged as: scheme://host:Port/path

URI can be a relative path or an absolute path