A peer-to-peer (P2P) network is not centrally controlled. It allows anyone with an internet connection to participate in sharing files. In a P2P network, the peers are usually computer systems connected in nodes. A blockchain is a typical example of a P2P network.
For crypto exchanges, a P2P platform allows buyers to pay sellers directly without involving third parties. A P2P exchange platform only serves trading operations and is not authorized to store funds. Therefore, the range of services a P2P exchange offers is much smaller than the range of services offered by centralized platforms.