P2P is the acronym for Peer-to–Peer.
Peer-to-Peer is a model of interaction that directly involves the necessary parties of a transaction. In traditional environments, whenever a transaction takes place there are a multitude of unrelated parties that are involved; for instance the credit card issuer, payment processor, shopping platform and so on. If that same transaction were to take place P2P then only the party selling and party buying are involved. Benefits of P2P environments include the reduction of transactional costs, privacy preservation, and communicative efficiency.