The definition of a node varies depending on the situation. In computer or telecommunication networks, nodes can serve as either a redistribution point or a communication endpoint. A node is typically made up of a physical network device. However, virtual nodes are occasionally employed.
What is a node?
A blockchain is made up of data blocks. These data chunks are stored on nodes (compare them to small servers). Any device can act as a node (mostly computers, laptops, or even bigger servers). A blockchain's infrastructure is made up of nodes. All nodes on a blockchain are linked together and regularly exchange the most recent blockchain data with one another, ensuring that all nodes are up to date. They store, distribute, and maintain blockchain data, so a blockchain can theoretically exist on nodes. A full node is a device (such as a computer) that stores a complete copy of the blockchain's transaction history.
What do nodes do?
When a miner tries to add a new block of transactions to the blockchain, it broadcasts it to all of the network's nodes. Nodes can accept or reject a block based on its legitimacy (validity of signatures and transactions). When a node accepts a new block of transactions, it saves and stores it on top of the previously saved blocks. In a nutshell, nodes do the following:
- Nodes verify the validity of a block of transactions before accepting or rejecting it.
- Blocks of transactions are saved and stored by nodes (storing blockchain transaction history).
- This transaction history is broadcast and spread by nodes to other nodes that may need to synchronise with the blockchain (need to be updated on transaction history).
Types of Blockchain Nodes
In a nutshell, full nodes and light nodes are the two sorts of nodes. Clients are another term for nodes that provide wallet functions. Full ones have a copy of the blockchain's history, including all of the blocks that have been produced. Light nodes, also known as SPV (Simple Payment Verification) nodes, are wallets that just download the headers of blocks, saving users' hard drive space. Let's take a closer look at the many sub-kinds.
1. Full Nodes
Full nodes act as servers in a decentralised network. Establishing consensus among other nodes and confirming transactions are two of their major roles. They also maintain a copy of the blockchain, which makes it more secure and allows for unique features such as quick transmission and secret transactions.
Full nodes are the ones who vote on suggestions when it comes to the future of a network. It is skipped if more than 51% of them do not agree with the proposition. In some circumstances, this can result in a hard fork, where the community cannot agree on a particular change and the chain splits into two. The Bitcoin Cash (BCH) Fork is the most well-known example of this happening.
Pruned Full Node - The pruned full node is one type. The unique feature here is that it starts downloading blocks from the beginning and deletes the oldest ones once the set limit is reached, retaining only their headers and chain placement. For example, if you set a size limit of 550MB, you will store all of the most recent blocks that can fit on that hard drive space, but in order to get there, you must first validate all of the previous blocks. Pruned nodes are considered full nodes. They can verify transactions and participate in consensus.
Archival Full Node - When most people talk about full nodes, they are referring to archival full nodes. They envision a server that will store the entire blockchain in its database. Their primary responsibility is to maintain consensus and validate blocks. The only distinction between pruned and archival nodes is the amount of hard drive space they consume on your server or PC. Archival nodes are classified into two types: those that can add blocks to the blockchain and those that cannot.
Archival nodes are further classified into the following groups:
- Authority Nodes - Anyone can join a public blockchain network and become a node by synchronising their system with the blockchain data. However, there are many instances where data access must be maintained. In this case, the Blockchain must be governed by specific authorised entities. This is where authority nodes come into play. These nodes are named after the fact that they control or are in charge of authorising other nodes to join the Blockchain network.In some blockchain platforms, authority nodes can even be in charge of determining which nodes have access to which data channels.
- Miner Nodes - Miners are nodes (either full or light) that try to prove that they've accomplished the requisite work to build a block, which you may already be familiar with. As a result, the nickname "Proof of Work" has gained popularity. As I explained before, miners must either be archive full nodes themselves or receive data from other full nodes on the network to know the current state of the blockchain and the requisite parameters for the next block in line to finish the task. Participants in the process use hardware components to solve cryptographic problems (such as CPUs, GPUs, and ASICs). The first individual to finish the task publishes his results to the network for full node verification, and after consensus is reached, he is given permission to add a block to the existing blockchain. Miners are paid a set quantity of coins in addition to any transaction fees for each block for their efforts. A coinbase, or a coinbase transaction, refers to the fixed reward amount. It's free since it's the first transaction in the block, which was produced and included by the miner himself.
- Staking Nodes - Other nodes, like miner nodes, are responsible for validating transactions on the network in order to keep the consensus method running. These nodes are required to stake their money, validate the transaction, and then be compensated for the process in one of the most popular algorithms, Proof-of-Stake. In staking, the node is chosen based on pre-defined criteria such as coinage or network time spent. The chosen node is then given the opportunity to validate a transaction and earn a reward. Staking nodes are nodes that do not require a lot of processing power.
- Masternodes - Masternodes, unlike full nodes, are unable to add blocks to the blockchain. Their sole duty is to keep track of and validate transactions. They're the ones who write blocks on the blockchain, whether they're miners or stakers. However, running a masternode has the extra benefit of allowing you to not only secure the network but also receive a share of the rewards for your efforts.
2. Light Nodes
The concept of lightning nodes is fascinating. The aim behind them is to create a link between people who are not connected to the blockchain. The stress on the network is lowered, transfer times are greatly reduced, and the usability of crypto currency is improved. The lightning network has extremely cheap transaction costs. The transaction costs, on average, range from 10 to 20 satoshis.
It operates by establishing a second payment channel between parties. Take John and a bagel shop, for example. John and the business build something akin to a safe-deposit box (a multi-signature address) with distinct keys for each of them. John puts his money in a savings account and utilises it to buy bagels. Each transaction is mutually agreed upon and takes place almost instantaneously. He or the shop can stop the connection after he or she has had enough bagels or simply runs out of money, then take the most recent balance sheet and broadcast it onto the network.
Rather than waiting for each transaction to be completed and cluttering the network with useless data, participants can engage with one another and reduce the burden on the blockchain this way. Furthermore, if another party wishes to transact with the same party, the lightning network will seek the shortest channel with the fewest middlemen and lowest transfer costs, thus minimising wait times.
Rather than waiting for each transaction to be completed and cluttering the network with useless data, participants can engage with one another and reduce the burden on the blockchain this way. Furthermore, if another party wishes to transact with the same party, the lightning network will seek for the shortest channel with the fewest middlemen and lowest transfer costs, minimising wait times.
Nodes are critical to the operation of a blockchain network because they keep all participants honest and assure data veracity. The majority of blockchain networks use monetary incentives such as mining or staking to encourage users to run full nodes. Regardless of the incentives, some users put up full nodes on their own initiative just because they believe in a project's future and want to help and safeguard it as much as they can.
Keep in mind, however, that running a complete node comes with expenses and hazards. Even though there are numerous guidelines available online, setting them up can be too complicated for folks who are unfamiliar with blockchain and programming.