The winning miner assembles transactions into a block and confirms them. It then broadcasts the block to the network to be reviewed by the nodes. Each node checks that everything in the block is valid and then adds the validated block to its blockchain.
Not every blockchain uses mining or has miners. There are other consensus mechanisms that use different methods to determine who validates transactions. For example, proof of stake requires that participants lock up their cryptocurrency funds as collateral to be part of the process.
Types of nodes in blockchain
The types of blockchain nodes are:
- Archival full nodes
- Pruned full nodes
- Light nodes
- Masternodes
- Mining nodes
- Authority nodes
- Staking nodes
- Lightning nodes
A single blockchain won't have all these types of nodes. The configuration depends on the blockchain and its specific needs. Here's a summary of each type of node in a blockchain:
Archival full nodes
An archival full node stores the entire blockchain ledger, meaning all the transactions from the beginning to the most recent. This type of node needs to have a large amount of memory available since blockchains can take up quite a bit of space.
Pruned full nodes
A pruned full node has a set memory limit. It downloads the blockchain, and then it deletes blocks starting with the oldest. This process is known as pruning, and blocks aren't fully deleted since their metadata and sequence remain. After pruning, this node will hold the most recent blockchain transactions up to its limit. For example, if the size limit is 1 GB, it will hold the most recent gigabyte of transactions.
Light nodes
A light node only downloads and stores block headers. Because it sticks to the essential data, it relies on full nodes to function and is used to process fast, simple transactions.
Masternodes
A masternode is a type of full node that validates transactions and maintains a record of the blockchain, but it can't add blocks to the blockchain.
Mining nodes
A mining node participates in the cryptocurrency mining process. Mining nodes are selected based on the blockchain's consensus mechanism. For example, with proof of work, the first mining node to solve a mathematical problem gets to confirm a block of transactions. A mining node may consist of one miner or a mining pool, which is a group of miners working together.
Authority nodes
An authority node is one that has been elected by the organization or community managing a blockchain. It's found in blockchains that have a vetting process required to be a node. For example, blockchains that use a proof-of-authority system only use approved nodes run by node operators who have provided identifying information.
Staking nodes
A staking node locks up cryptocurrency funds as collateral, which is known as staking. Blockchains that use a proof-of-stake system select staking nodes to confirm blocks of transactions. A staking node may consist of one user or a staking pool, which is a group of users who pool their crypto funds to have a better chance of being selected to confirm blocks.
Lightning nodes
A lightning node creates a separate network for users to connect to off the blockchain, enabling off-chain transactions. The transactions are processed and then submitted to the main blockchain. Lightning nodes are useful on congested blockchain networks with slow processing and high transaction fees. These nodes allow for low-cost, near-instantaneous transactions.
