What Is a URI?

What Is a URI?

URI stands for "Uniform Resource Identifier." A URI is a string used to identify or refer to a resource. This resource can be a file, a web page, or a service. URI ensures the unique identification of resources on a global scale.

A URI might look like this:

This example is a URI that identifies a web resource. However, URIs are not limited to web addresses; they can also include email addresses and other types of resources.

What Is a URL?

URL stands for "Uniform Resource Locator." A URL is a type of URI that specifies where a resource is located and how to access it. URL is one of the most common formats used to address a resource.

A URL consists of the following components:

• Protocol: The communication method used to access the resource, such as https.
• Domain Name: The address of the server where the resource is located, such as www.example.com.
• Path: The directory used to access a specific resource on the server, such as /index.html.

An example URL could look like this:

What Is the Difference Between URI and URL?

URI and URL are often used interchangeably, but there are important differences:

• Definition: URI is a general term that identifies or refers to a resource. URL is a subset of URI that specifies the location of the resource.
• Focus: URI focuses on identifying the resource, whereas URL focuses on how to access the resource.
• Scope: Every URL is a URI, but not every URI is a URL. For example, a URN (Uniform Resource Name) is a type of URI that identifies a resource but does not specify its location.

Example:

• URI:urn:isbn:0451450523 (Identifies a book but does not specify its location.)
• URL:https://www.example.com/book/0451450523 (Specifies the location of a book.)

Should I Use URI or URL?

Which term to use depends on what you want to express:

• If you want to specify the location of a resource: You can use the term URL.
• If you want to generally identify a resource: The term URI would be more appropriate.

In web development and everyday use, the term URL is more common. However, in technical documentation and standards, URI is more frequently used. For example:

• If you are specifying a web address: "URL" is suitable.
• If you are referring to both the identifier and the locator of the resource: "URI" should be used.

In general, the term URL is more well-known and widespread in modern usage. However, URI is encouraged for its technically accurate and comprehensive meaning.