Glossary
Link shortener and analytics terms, explained
Plain-English definitions of the terms behind short links, redirects and the analytics that come with them.
Term
301 vs 302
Permanent and temporary redirects. The difference decides whether browsers cache the hop, which decides whether you can count it or change it later.
Term
Attribution
Deciding which placement, campaign or channel deserves credit for an outcome.
Term
Back-half
The part of a short link after the domain: the key the server looks up to find the destination.
Term
Bot traffic
Automated requests to a link that no person made: previews, security scanners, crawlers and monitoring.
Term
CNAME record
A DNS record that points one hostname at another, which is how a custom domain is attached to a shortener.
Term
Custom domain
A domain you own, pointed at a link shortener, so your short links carry your name instead of the shortener's.
Term
IP geolocation
Estimating where a visitor is by looking their IP address up in a database of allocated ranges.
Term
Link rot
The steady failure of published links over time, as destinations move, sites close, or the service in the middle shuts down.
Term
Open redirect
A URL on a trusted domain that will forward a visitor to any destination given to it, which attackers use to borrow that domain's reputation.
Term
QR code
A two-dimensional barcode that encodes text, usually a URL, so a camera can open it without anyone typing.
Term
Query string
The part of a URL after the question mark, carrying key and value pairs that travel with the request.
Term
Redirect
An HTTP response that tells the browser to go somewhere else, using a 3xx status and a Location header.
Term
Referrer
The page a visitor came from, as reported by their browser in the Referer header, when it reports one at all.
Term
Referrer-Policy
A header a site sends to control how much of its URL is passed on when someone follows a link away from it.
Term
Short link
A brief URL that redirects to a longer one, used to make links shareable, printable, and countable.
Term
Unique clicks
An estimate of how many separate people opened a link, as distinct from how many times it was opened.
Term
User agent
A string a browser sends identifying itself, its version and the operating system, from which device and browser breakdowns are derived.
Term
UTM parameters
Tags added to a URL's query string that name where a link was published, so analytics can tell one placement from another.