EMV is the global standard for chip and contactless card payments, maintained by EMVCo. The contactless tap on a card runs on EMV over NFC.
The longer version
EMV is the standard behind chip cards and the contactless taps they support. It is the tap to pay card standard, maintained by EMVCo on behalf of the card networks. When people tap a card at a terminal, they are using EMV.
On a contactless card, EMV runs over NFC. The card and terminal communicate within the few centimetres NFC allows, so a contactless tap is still a close, deliberate gesture offered to a reader. EMV defines the card and terminal side of that exchange.
Because EMV assumes a card offered to a reader, it does not address which of several people in a space is nearest, and it does not route around the terminal. Sensing presence without a deliberate tap, and routing the result through a server, sits outside what the EMV card standard was built to do.
The Parousya method
EMV standardizes the tap the Parousya method aims to move past. Where EMV expects a card offered to a reader, the method identifies the payer by presence and routes the transaction through a central server instead.