By validating and propagating transactions and blocks, the Bitcoin node plays a fundamental role in the proper functioning of the protocol.
A Bitcoin node is a computer on which the protocol software is installed and running. Nodes work together through a peer-to-peer network to receive, validate, and transmit transactions and blocks on the blockchain. Currently, the nodes in the Bitcoin network number over 17,000, not counting those hidden under the Tor or VPN network. It is estimated that there are over 60,000 nodes in total.
What is the purpose of a Bitcoin node?
Firstly, a node helps preserve the integrity of the Bitcoin network by ensuring that all transactions adhere to the rules established by the protocol. This includes making sure that new transactions and blocks are valid.
Secondly, Bitcoin nodes enhance the resilience and distribution of the network: with thousands of nodes scattered worldwide, the Bitcoin network is very difficult to attack or suppress.
Finally, nodes enable the functioning of the network in a peer-to-peer way, without the need for intermediaries.
Why have a Bitcoin node?
Owning a node means being part of the network, contributing to its distributed nature.
The key advantages of having a node are:
- Security and control: you have complete control over your transactions and can verify each transaction on the blockchain;
- No intermediaries: you don’t rely on any third-party intermediaries or services when transmitting a transaction;
- Greater privacy: by connecting the node to your wallet, you achieve a higher level of privacy, as no external server is queried.
Types of nodes
In the Bitcoin network, all nodes are equally important, but there are different types:
- Full-node: they are called so because they maintain a copy of the entire blockchain. This gives them the ability to independently verify each transaction without relying on external references. Moreover, full-nodes allow mining activity for those with suitable hardware, such as ASIC machines. They can also serve as wallets for sending and receiving payments;
- Pruned Node: these nodes, once they verify all transactions on the blockchain, only store a portion of it to save storage space;
- SPV (Simplified Payment Verification): also known as lightweight nodes, SPV nodes maintain a minimal part of the blockchain, focusing on block headers and thus not fully verifying all transactions ever made;
- Full Blockchain Node: these nodes primarily handle the transmission and verification of transactions. While they maintain a complete copy of the entire blockchain, they cannot be used as wallets and do not support mining activity;
- Miner: these nodes are dedicated to mining activity, provided the user has the necessary hardware. They do not support connections with wallets.
What is needed to build a node?
To build a node, all you need is a computer with fairly modest specifications. The most important components to have are a memory unit of at least 1 TB, a minimum of 2 GB of RAM, and an unlimited Internet connection.
The most widely used full-node implementation is Bitcoin Core. By downloading the program from the official website, you can set up your own node.
Over the years, several ‘distributions’ have also been developed, allowing for the easy and fast setup of a personal Bitcoin full-node. The most well-known ones include MyNode, Umbrel, RaspiBlitz, Start9, and Citadel.