URL

URL is an acronym to uniform resource locator

Examples of URL:

helioalbano.me/hello/world.html, here, the URL is helioalbano.me

site.com/content.html, here, the URL is site.com

URN

URN is an acronym to uniform resource name

Examples of URN:

helioalbano.me/hello/world.html, here, the URN is hello/world.html

site.com/content.html, here, the URN is content.html

URI

URI is an acronym to uniform resource identifier

URI is the union of http:// or https:// + URL + URN

Examples of URI:

https://helioalbano.me/hello/world.html

http://site.com/content.html