[Network] Differences between URI and URL

1. Introduction

Recently, I have been reading a lot of network-related web documents or books, and I write a posting to organize it once because it is so confusing to call it a URL in some parts and URI in others. When looking at it without knowing it, it seems to be similar in shape, but I wonder what the difference is. From now on, let's find out the difference clearly.

2. What is URI(Uniform Resource Identifier)?

Uniform Resource Identifier (URI)
 consists of a string of characters used to identify or name a resource on the Internet

3. What is URL(Uniform Resource Locator)?

Uniform Resource Locator (URL)
 colloquially termed a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it.

Most importantly, the URL is included in the URI.

4. Example of separating URI and URL

1. https://example.io is a URL and URI because it represents a server named https://example.io.

2. https://example.io/images is a URL and URI because it refers to the location of resources on the network called images on the example.io server.

3. https://example.io/images/dog.jpeg is a URL and URI because it points to dog.jpeg under the images directory on the example.io server.

4. For https://example.io/user/123, the URL is https://example.io/user and includes identifier 123 to reach the desired information, which is a URI. In other words, it is a URI but not a URL.

5. https://example.io/profile?id=11 is also a URL to https://example.io/profile, but includes an identifier ( ?id=11) to reach the desired information, which is a URI. In other words, it is a URI but not a URL.

[References]

• https://en.wikipedia.org/wiki/URL
• https://en.wikipedia.org/wiki/Uniform_Resource_Identifier
• https://medium.com/@js230023/url-%EA%B3%BC-uri%EC%9D%98-%EC%B0%A8%EC%9D%B4-154d70814d2a
• https://lambdaexp.tistory.com/39#:~:text=URI%EB%8A%94%20%EC%9D%B8%ED%84%B0%EB%84%B7%20%EC%83%81%EC%9D%98%20%EC%9E%90%EC%9B%90,%EC%9C%BC%EB%A1%9C%20%ED%95%B4%EC%84%9D%20%EB%90%A0%20%EC%88%98%20%EC%9E%88%EA%B2%A0%EB%8B%A4.&text=URI%EC%9D%98%20%ED%95%9C%20%ED%98%95%ED%83%9C%EC%9D%B8,%EC%9D%84%20%ED%8F%AC%ED%95%A8%20%ED%95%98%EB%8A%94%20%EA%B0%9C%EB%85%90%EC%9D%B4%EB%8B%A4.
• https://dev.to/flippedcoding/what-is-the-difference-between-a-uri-and-a-url-4455