Cirrus (interbank network)
Cirrus is a worldwide interbank network that provides cash to Mastercard cardholders. As a subsidiary of Mastercard, it connects all Mastercard's credit, debit, and prepaid cards, as well as ATM cards issued by various banks worldwide bearing the Mastercard/Maestro logo.
Source: Wikipedia — Cirrus (interbank network) (CC BY-SA 4.0)