<p><span style="font-weight: 400;">We discussed the role of nodes in the authenticity and execution of a transaction. But let us explore them further. Nodes are devices connected to the blockchain by independent companies or users. The computing power of the nodes is used to provide services to anyone interested in using blockchain. In theory, anyone can install the blockchain software and become a node but in practice, the computing power of the device and some other requirements must be fulfilled. These peer-to-peer nodes form the blockchain network. There are different types of nodes:</span></p>
<h3><strong>Full Nodes</strong></h3>
<p><span style="font-weight: 400;">The full nodes hold a copy of the entire blockchain ledger and ensure the correctness of the data. One full node holds all the information of a blockchain, including transactions and all the blocks. Full nodes also accept transactions and blocks from other full nodes to validate them and dispatch them to other full nodes in the network.</span></p>
<h3><strong>Light Nodes and Payment Verification</strong></h3>
<p><span style="font-weight: 400;">The light nodes only keep a copy of the block header and not the complete blockchain. They are also known as SPV nodes as they use the Simplified payment verification (SPV) method for transaction verification. They check the presence of a transaction in a block by using the information from a Merkle tree.&nbsp; The hash of the transaction is verified without downloading the entire blockchain. The functioning of light nodes depends on the information provided by full nodes.</span></p>
<h3><strong>Mining Nodes</strong></h3>
<p><span style="font-weight: 400;">Once the full nodes reach a consensus on a transaction, they announce it to the miners. The miner nodes are the ones who add the block to the blockchain, and the process is called mining. As only one miner can add a block to a blockchain, the miners must solve a puzzle to qualify for mining. The miner who solves the puzzle first gets to mine the block. The miner then communicates securely with other full nodes on the network. The mining software requires strong computing power to solve complex mathematical puzzles.</span></p>
<h3><strong>Incentive to Miners</strong></h3>
<p><span style="font-weight: 400;">Mining nodes or miners are the ones who create blocks and help in completing a transaction. A lot of computational power goes into mining the blocks and miners manage that on their own. So, there must be an incentive for them to spend money and other resources on mining.</span></p>
<p><span style="font-weight: 400;">A sender, one who initiates a transaction, sends information to the miner that is used to create a block. Keeping the information specific and minimum is a way to incentivize the miner. More information equates to more resources and the miner may choose another transaction in place of the one which has too much information.</span></p>
<p><span style="font-weight: 400;">Miners also get a transaction fee from the sender. The fee is added to the transaction in cryptocurrency. Block rewards are also a form of incentive for the miners who get cryptocurrency for every block they create.&nbsp;</span></p>