Cryptopedia
Node
Node
In terms of blockchain technology, any computer or device that has a cryptocurrency app, which can be downloaded from the cryptocurrency official website, and connects to that cryptocurrency blockchain interface can be considered as a node.
Decentralization of blockchains allows the information to be supervised by distributed servers, namely the nodes, instead of a central server. As the minimum units on the blockchains, nodes can verify and transmit information to each other, and construct a whole blockchain by storing information. Nodes play significant roles in maintaining security, integrity and running of a blockchain. Generally speaking, if there are more nodes in a blockchain, the blocks will be safer.
Normally, the nodes can be divided into the Full Node and the Light Node according to the information-storage ability and functions.
Full Node
A full node, usually held by the miners, can store all the information of the blockchain of the original block to the latest block.
A full node will verify each piece of information that is to be added on the blockchain to ensure the new information is within the blockchain protocol. For example, when A launches a transfer, the full node will lock on A’s account by scanning all the blockchain ledgers to check whether A has the ability to pay with the balance and continue verifying if A has done the same payment before in order to avoid the double-spending problem (the money that has been paid twice). Based on the above procedure, A can be verified whether he is qualified to hold the account. If no problem arises during the process, A’s transfer will be confirmed; otherwise, A's transfer will be refused by the full node.
However, there are some requirements for computers to run a full node; it needs powerful computing ability and data-processing capabilities to deal with the storing and verification. Owing to the enormous resource and money consumed by the full node, those who are willing to run a full node can gain transaction handling charges and cryptocurrencies.
Light Node (Light Client)
A light node does not store or verify any information or transactions on the block. It only applies to the users who only have basic investment, consumption and payment needs, or who do not want to keep a copy of the blockchain.
A light node works through SPV (Simplified Payment Verification). When there is a transaction, SPV will connect to the full node and download the information of all the block headers, based on which this transaction will be verified if it is valid and how many times it has been verified before. The payment will be allowed only if verification is passed.
In terms of blockchain technology, any computer or device that has a cryptocurrency app, which can be downloaded from the cryptocurrency official website, and connects to that cryptocurrency blockchain interface can be considered as a node.
Decentralization of blockchains allows the information to be supervised by distributed servers, namely the nodes, instead of a central server. As the minimum units on the blockchains, nodes can verify and transmit information to each other, and construct a whole blockchain by storing information. Nodes play significant roles in maintaining security, integrity and running of a blockchain. Generally speaking, if there are more nodes in a blockchain, the blocks will be safer.
Normally, the nodes can be divided into the Full Node and the Light Node according to the information-storage ability and functions.
Full Node
A full node, usually held by the miners, can store all the information of the blockchain of the original block to the latest block.
A full node will verify each piece of information that is to be added on the blockchain to ensure the new information is within the blockchain protocol. For example, when A launches a transfer, the full node will lock on A’s account by scanning all the blockchain ledgers to check whether A has the ability to pay with the balance and continue verifying if A has done the same payment before in order to avoid the double-spending problem (the money that has been paid twice). Based on the above procedure, A can be verified whether he is qualified to hold the account. If no problem arises during the process, A’s transfer will be confirmed; otherwise, A's transfer will be refused by the full node.
However, there are some requirements for computers to run a full node; it needs powerful computing ability and data-processing capabilities to deal with the storing and verification. Owing to the enormous resource and money consumed by the full node, those who are willing to run a full node can gain transaction handling charges and cryptocurrencies.
Light Node (Light Client)
A light node does not store or verify any information or transactions on the block. It only applies to the users who only have basic investment, consumption and payment needs, or who do not want to keep a copy of the blockchain.
A light node works through SPV (Simplified Payment Verification). When there is a transaction, SPV will connect to the full node and download the information of all the block headers, based on which this transaction will be verified if it is valid and how many times it has been verified before. The payment will be allowed only if verification is passed.
