Bitcoin is a decentralized peer-to-peer network made of computers, or nodes, that run the Bitcoin software and accept a set of proof-of-work (PoW) consensus rules to validate and broadcast transactions on the blockchain. This process occurs without the intermediation of a third party, making blockchains trustless mechanisms.
In the Bitcoin blockchain, traditional third-party payment systems are replaced by a distributed network of node operators and miners who validate transactions without censorship or permission.
Anyone can become a Bitcoin node operator and participate in securing the network by simply downloading the Bitcoin Core software, thus making the blockchain transparent, immutable and decentralized.
What is a Bitcoin node?
Nodes are pillars of the Bitcoin network. These nodes continuously monitor the blockchain and its complete transaction history to prevent access to non-legitimate transactions that attempt to spend their Bitcoin twice fraudulently, also known as the double-spending issue.
Any computer downloading the Bitcoin software that will join the Bitcoin network is called a node. The most popular client and software implementation of full nodes is Bitcoin Core; its latest release can be found on the GitHub page.
A node holds the complete history and chronology of the Bitcoin blockchain, which is like a ledger, and contributes to the security of the Bitcoin network through the consensus mechanism because nodes will reject any transaction that breaks consensus rules.
How many Bitcoin nodes are there? It is difficult to assess the exact number of active Bitcoin nodes, as users can choose to connect privately in order not to reveal or count them.
There are very contradicting figures between one source and another. Some sources only calculate that there are just over 13,000 Bitcoin nodes. On the other hand, popular Bitcoin Core developer Luke Dash Jr estimated about 83,000 Bitcoin Core nodes were active in Jan. 2021 while recording a steep decline in 2022 to roughly 50,000.
The data is even more alarming, considering over 200,000 Bitcoin nodes were running at the peak of the 2017 bull market. The more active and connected nodes to the Bitcoin network, the more robust and decentralized it becomes.
How do blockchain nodes work?
Nodes validate and broadcast transactions to the network. These transactions showing as “pending” are picked up by a miner or a mining pool that will add them to the blockchain’s universal ledger.
Instead of confirming each individual transaction, miners will batch pending transactions into blocks. The confirmed block is disseminated across the entire network and sent back to all nodes to ensure the block is valid and adopts the network’s rules.
Once validated, the nodes add the new block to the previous series of blocks, thus creating a blockchain and achieving transactions’ final settlement.
