What is the difference between Master and Visa cards? And which card is the best?

 There is no difference between Visa card and Master card.

The main difference is that the two cards are from two different companies.
Every transaction of Visa card is done through Visa company or Visa network i.e. that bank has a contract with Visa company and you are given a Visa card and every transaction of that card is done by Visa company and that bank.

In the same way, every transaction of MasterCard is done through MasterCard or MasterCard network and that bank is contracted with MasterCard company and every transaction is done by that bank and that company together.

Which is better or which one you will take

Bangladesh is a very good two card network.
You can choose any one for you. Very secure and reliable in two card transactions. With these cards you can withdraw money from any ATM in Bangladesh and if your Visa or MasterCard supports dual currency then you can withdraw money from any ATM in the world.

Now if you need a specific card for a specific job, then you can choose that specific card for you.

For example, if a company only supports MasterCard for payment and if you have to make frequent transactions with that company, then you can choose MasterCard for you.