Tap to pay is contactless payment made by holding a card or phone within a few centimetres of a reader, over NFC. It removed the swipe and the dip, but it still requires a deliberate gesture.
The longer version
Tap to pay is the contactless checkout most people know. An NFC card or phone comes within a few centimetres of a terminal, the two exchange over that short link, and the payment clears. It is faster and cleaner than a magnetic stripe.
The gesture is the point and the limit. Tap to pay still asks the payer to produce a device and aim it at a reader. In settings where hands are full, or where there is no reader to tap, the deliberate gesture becomes friction of its own.
Proximity payment keeps the ease of contactless but drops the aimed gesture. Presence over a longer range signal stands in for the tap, and the transaction routes through a server rather than across the reader link. The payer can be recognized without presenting anything.
The Parousya method
Tap to pay is the closest familiar reference point for the Parousya method, and the clearest contrast. The method reaches the same clean checkout, but presence replaces the tap and server routing replaces the reader link.