Nodes — Know more about Peer-to-Peer

To understand what peer-to-peer (P2P) is, imagine 6 computers and a music file. Five computers out of the six have that music file, and, for example, you are the sixth computer that wants to have this file, too. Normally, you would download it from a central place, i.e. from a server, but utilizing the peer-to-peer method, you can get this file from nodes (peers).

P2P computing or networking is a distributed application architecture where the nodes are equipotent participants of the network. Blockchains cannot be modified by anyone, because in order to change anything in this distributed ledger, you have to modify every blockchain that is stored by the nodes.

Bitcoin is a distributed, open, peer-to-peer system. There is no “central” server or centralized control. Bitcoin nodes maintain a local copy of the blockchain, starting at the genesis block. The local copy of the blockchain is constantly updated with new blocks what are found by the miners. This distributed ledger backed by every participant of the bitcoin network. The rules of the bitcoin protocol is secured by the nodes (peers) in peer-to-peer way.

Any computer that is connected to the bitcoin network is called a node. Nodes receive the blocks, then link them to the existing blockchain and verify these blocks falling all of the rules of the Bitcoin protocol. Bitcoin transactions are broadcast to the network by the sender, and all peers who are trying to solve the blocks collect the transaction records and add them to the block they are working to solve.

Looking at a new block, the node finds the “previousblockhash” field, which contains the hash of its parent block. It is a hash known to the node, which is of the last block on the chain at height 615030. Therefore, this new block is a child of the last block on the chain and extends the existing blockchain. The node adds this new block to the end of the chain, making the blockchain longer with a new height of 615031.