It’s another way of saying Peer-to-Peer. Peer-to-peer is a decentralized communications model in which each party has the same capabilities and either party can initiate a communication session. Unlike the client/server model, in which the client makes a service request and the server fulfills the request, the P2P network model allows each node to function as both a client and server.
In regards to currencies, P2P is used to describe the decentralized cryptocurrency model, or those currencies not created by a central bank (known as fiat currency). Cryptocurrencies are considered P2P because they are exchanged electronically between two parties, without the need for a centralized exchange or middle-man such as a bank or other financial institution and because they are created digitally and are managed by a decentralized network of computers that is not maintained by the government or any other centralized authority. P2P currencies do depend on an internet connection to function.