First digital credit card number tells the network of credit card

 

Credit card No. starts with Network
3 American Express
4 Visa
5 Master Card
6 Discover
Almost all credit cards have a standard size: 3.375 inches by 2.125 inches. It is ID-1 size which is the standard “credit card” size for identification cards defined by ISO/IEC 7810

Material of credit card is mostly plastic. However, some premium credit cards use metal.

Citibank mostly issues credit cards on MasterCard network. Only Visa credit card issued from Citibank is Costco credit cards
Chase mostly issues credit cards on Visa network. Only MasterCard from Chase is Freedom Flex
All Discover credit cards have no annual fees
Discover gives the option to select the color of the credit card
Chase Disney Premier credit card lets you select the card image