Online identifier
A piece of data — like an IP address or device ID — that can single you out online.
An online identifier is a piece of information — such as an IP address, a cookie ID, or a device identifier — that can be used, on its own or together with other data, to single you out online. Under data-protection law these count as personal data, which means the same rights of access and erasure can apply to them. Treating these as personal data keeps your fundamental rights meaningful in a world where much of what identifies you is technical rather than a name.