URL vs URI: Key Differences Explained in Simple Terms
A URL (Uniform Resource Locator) is the complete web address you type—protocol, domain, path, and all. A URI (Uniform Resource Identifier) is the broader umbrella that can name, locate, or just identify a resource, even if it never points to the web.
People confuse them because every URL is technically a URI, but not every URI is a clickable link. Imagine ISBNs for books: they’re URIs that identify, yet you can’t “click” them.
Key Differences
URL = locator (where). URI = identifier (what). A URL must specify a retrieval method like https://. A URI might be urn:isbn:1234567890—pure identifier, zero retrieval. Think: all thumbs are fingers, but not all fingers are thumbs.
Which One Should You Choose?
For clickable links on the web, use URL. For naming resources inside code, APIs, or databases where retrieval isn’t required, URI works. Most devs say “URL” out loud even when they mean URI—industry habit wins.
Is a QR code a URL or URI?
It can hold either. If it encodes https://example.com it’s a URL. If it stores a URN or tag, it’s a URI that may not be web-accessible.
Can a URI become a URL later?
Yes. Assign a URN today, add an http endpoint tomorrow—it graduates from pure identifier to full-blown locator.
Do browsers care about the difference?
Not visibly. They parse what you type; if it resolves, they load it. Under the hood, specs treat URLs as a subset of URIs.