Peer-to-peer (P2P) is a concept which facilitates the exchange of information and data directly between two or more users. This type of network has no centralized entity or server and instead relies on distributed nodes (computers connected to the network).
They create a mesh of nodes in which each node is connected with one another. In the case of blockchains, it is used to transfer cryptocurrencies between users or to participate in the consensus mechanism of the protocol itself. P2P allows nodes to communicate and exchange data quickly and securely, creating a distributed system instead of a centralized one.
Each node is equal without the presence of master nodes or other single points of failure. Compared to centralized networks it also provides anonymity, privacy and security to all nodes in the network. This concept goes far beyond cryptocurrencies as it allows users to access services without relying on trusted third parties.
This concept can be applied to many other systems and networks. It also creates greater resilience in the event of the loss of single nodes. P2P technology has been around for a long time but gained traction with the application in blockchain networks.