Austria, Germany, and the Netherlands use Maestro cards a lot more than other countries. If you’ll be spending a lot of time in any of those three countries, a Maestro card might be a good idea. If not, you might not need one.
Mastercard makes Maestro, which is a brand of debit card. Maestro cards can be used to buy things in stores and get cash from ATMs. Depending on the bank that issued the card, most Maestro cards can also be used to pay online.