- URI: An indicator of where a resource is. This means that multiple URIs can point to the same resource but are themselves different addresses. Following a URI might take any number of hops or redirections until it actually arrives at the resource.
- URL: a stricter term that identifies the exact location of a resource. This subtle difference has blurred over time such that nobody cares about the difference. I will continue to use the term URL, because people are more comfortable with it.