Maestro is a multi-national debit card service owned by MasterCard that was founded in 1992. Maestro cards are obtained from associate banks and can be linked to the card holder’s current account, or they can be prepaid cards. The cardholder presents the card at the point of sale (POS) and this is swiped through the payment terminal by the assistant or the customer or inserted into a chip and PIN device. The payment is authorized by the card issuer to ensure that the cardholder has sufficient funds in their account to make the purchase and the cardholder confirms the payment by either signing the sales receipt or entering their 4 to 6-digit PIN. It is most widely used in Europe.
Visa Inc. is an American multinational financial services corporation headquartered in Foster City, California, United States. It facilitates electronic funds transfers throughout the world, most commonly through Visa-branded credit cards and debit cards. Visa does not issue cards, extend credit or set rates and fees for consumers; rather, Visa provides financial institutions with Visa-branded payment products that they then use to offer credit, debit, prepaid and cash-access programs to their customers. It was founded in 1958 as BankAmericard.
Similarly, MasterCard is a International Payment franchise which also has a large worldwide acceptance and it’s own network to process the payment transactions . It’s headquarter is in New York. It was founded in 1966 (as Interbank Card Association)
1979 (as MasterCard).
In USA, Visa is accepted more than MasterCard but outside USA, even MasterCard gives tough competition to Visa.
This answer is written by Ishant Sharma, SW Engineer at Visa on quora