NFC (Near Field Communication) is a wireless communication used to establish a connection between portable devices, over a very short distance, only up to 4cm. Previously, NFC was used to transfer photos and videos, but you'll often hear about it in connection with contactless payments.
If the bank supports this payment method, your NFC-compliant phone and a suitable application will suffice. Simply put the phone on the payment terminal as well as the contactless payment card, which also includes NFC elements. Technology works only in the immediate vicinity of the second compatible device (phone or payment terminal). Therefore, both devices must almost touch in order for NFC communication to work.