Maestro
In short: Maestro is Mastercard’s debit card brand, which could be found on many girocards as an additional logo.
In more detail: With the girocard one could pay abroad via Maestro. Mastercard has, however, phased the brand out: new Maestro cards have no longer been issued in Europe since July 2023.
In Depth
Successor
Banks are switching to Debit Mastercard or Visa Debit. The girocard remains for domestic use in Germany; for abroad you need a new co-branding. See Mastercard, Visa, online banking.
See also: Mastercard, Visa, Online Banking