URI和URL的區別

From RFC 3986:

A URI can be further classified as a locator, a name, or both. The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network "location"). The term "Uniform Resource Name" (URN) has been used historically to refer to both URIs under the "urn" scheme [RFC2141], which are required to remain globally unique and persistent even when the resource ceases to exist or becomes unav

ailable, and to any other URI with the properties of a name.

URI統一資源標識符 。至關於立了一個規矩：好比姓名的組成是  姓+名；

URL統一資源定位符   我根據這個規矩起了一個名字：李（姓）+小龍（名），注意這個李小龍是惟一的，世界上就一個叫李小龍的，你根據李小龍這個名字只能找到一我的。

URN 統一資源名