Bitcoin Forum

What are full nodes, how are full nodes important? Can the bitcoin network be possible without having the full nodes. Miners verify transactions, are they having full nodes to verify transactions?

Full nodes generally propagate the network. They help verify transactions and blocks and then distribute them.

You don't necessarily need (many) full nodes to keep bitcoin and similar cryptocurrencies working but they do help to increase bandwidth and initial sync speeds (miners, block explores and a few other services run full nodes for profit anyway and the network could likely survive just off that).

This is a good and precise definition from Bitcoin.com that might be of some help.

'A Bitcoin full node is software that allows businesses and advanced users to validate transactions and blocks on the blockchain of their choice. Running a full node is a read-only access to the blockchain. It does not give you power over the network, simply the ability to monitor it. For the majority of end-users, full nodes aren't required to run.'

Any nodes that have the full blockchain are called full nodes, any nodes that do not have the blockchain are not full nodes. Full nodes are keeping records of updated blockchain ledger.

Full nodes verify bitcoin transactions, a full node will verify transactions and relay it to another nodes through routing for further verification.

No, not possible.

Miners do verify transactions, miners mine new blocks and confirmed bitcoin transactions, nodes( nodes with full blockchain) are regarded as full nodes and are the ones that can further verify the transactions confirmed and blocks mined by miners. After a node verify a transaction it route it to another node for further verification.

Full nodes can help to increase your privacy if you broadcast your transaction from your node and does not reveal your real IP address to other nodes.

Read-only access to the blockchain? What does the meaning?

Full nodes require big disk space and your computer will not work normally if you run a full node and work with your usual tasks. Your computer will become very slow.
You need more than 320 GB to run a full node.
https://www.statista.com/statistics/647523/worldwide-bitcoin-blockchain-size/

Electrum (not good for privacy) and Wasabi wallet (good for privacy) are alternatives.

Nodes can still see your IP address. They just cannot ascertain if the transaction that you have broadcasted to them belongs to you or if you're merely someone who received and relay the transaction. As to why it provides more privacy than traditional SPV client, they don't send any addresses (bloom filter or not) to other nodes. It does not mean that it will enhance your privacy; it will depend on your spending habits. SPV clients like Wasabi will provide more all-around privacy.
I'm inclined to think that they're implying that you will be able to see the blocks but you won't be able to modify anything within that which would affect any other nodes as you won't have sufficient POW to build a new block, etc.
Not true. Bitcoin Core uses fairly low resources (in terms of CPU). I'm able to run my full node while gaming or video encoding as well. It really doesn't use that much resources after the initial block download, receiving and validating new blocks would at most result in a small spike in CPU usage.

Any participant who is running complete software of Bitcoin blockchain which is 321gb in size at this time(which keeps on increasing with time) is regarded as full node.Full nodes do not depend upon third party for any information as they have full record of each and every transaction of all registered address in the blockchain with them.Whenever a transaction is made on the network it is quickly prompted to the full nodes across the network which are connected with the wallets from which transaction input has been initiated and they are responsible for verifying the transaction that has been made.Full nodes are integral part of Bitcoin network as they are responsible for the transactions verification across the network and keeping record of that transactions.Miners are responsible for mining new blocks by solving cryptographic puzzle and adding transactions to that particular block in return of 6.25 btc block mine rewad + transaction fees of all transactions added to his block in the blockchain.So it's a proper chain system in which each and every participant is responsible for his functioning.

In simple terms Full nodes are computer clients which has the whole blockchain downloaded to their computers. Full nodes are also called as peers. Hence bitcoin network is called as a peer to peer network.
Full nodes increase the robustness of the bitcoin network by keeping it decentralized. Full nodes validates the blocks and adds them to the longest chain. A block receives one confirmation when it is added to the longest chain. When another block is added on top of the current block it receives 2 confirmations and so on. A block is added every 10 minutes approximately. Full nodes are important because they keep the bitcoin network secure.


Well technically miners do validate the transactions by referencing it through the consensus rules. Miners reject any transaction if they are invalid and add the valid transactions to the block. Source : Mastering Bitcoin


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I have corrected that above based on mastering bitcoin. But, I have a question, normally in a pool mining, no nodes for verification, miners in this case depends on pool server, in this process if one of the miners in the pool mine a block, the miner will not be able to verify? I believe after it mine a block, it will still have to depend on the pool server that has the blockchain for verification? Or, after a block is mined, the mining is the first verification?

Your phrasing is a bit confusing so I'll just answer this based on how I interpret your question.

It is correct that every miner should be a node, or at least have the capabilities to validate all the transactions and preferably also be able to validate the blocks that it receives.* The miners in a pool will at no point receive sufficient data or have sufficient data to validate anything; they don't have UTXO, they don't receive the entire block from the pool. When a pool receives a new block, the pool validates the block and if it passes validation, they will send the block header together with the hashes to the miners and they will start compiling the block headers to hash it.

A pool has to be able to validate transactions. If they are unable to do so, they cannot determine the valid transactions to be passed onto the miners mining in that pool. Miners within a pool doesn't need this, they trust that the mining pool is able to discern valid blocks and valid transactions.

* As for this, I imagine if you were able to SPV mine and just trust a reliable source (some block explorers) for the hash of the tip, target, etc , you can probably just mine empty blocks and you wouldn't need to validate anything. Of course, no one does this.