<p>Miners role is not to <em>validate</em> transactions, but to <em>confirm</em> them. Every node validate every transaction every time. A single invalid transaction would invalidate the entire blockchain.</p>

<p>In Bitcoin technology the transaction is collection of bytes. All the information about a transaction is the very transaction itself.</p>

CC BY-SA 3.0
2018-03-07T04:23:41.000Z
For eg. If A wants to give 5 bitcoin (for an instance) to B and A has only 3 bitcoin with him. In this case how this invalid transaction would be invalidated by other nodes? And here another question arises how blockchain helps to prevent duplication of bitcoins?  And also if the transaction is validated by other nodes then why there is a need of miner to confirm those same transaction?
Mansi Goel
CC BY-SA 3.0
2018-03-07T12:00:43.737Z
If A wants to spend more bitcoins he has, he will setup this invalid transaction in his computer. So he'll send that transaction to another computer running bitcoin. That computer will read the transaction received via the internet, see it's invalid (spend more than it can) and delete it from its memory.

No other node will accept or relay invalid transactions.

Your third question is the answer to the second one: miners confirm transactions to prevent duplication of spending. Read more here: https://bitcoin.stackexchange.com/questions/148/what-exactly-is-mining
Osias Jota
CC BY-SA 3.0
2018-03-07T03:15:10.967Z
2018-03-07T03:15:10.967Z
Osias Jota
<p>How miner validates each transaction? Does he have all the information  of the transaction taking place between nodes?</p>

<p>Thank you.</p>

CC BY-SA 3.0
2018-03-06T17:19:10.420Z
I'm not sure I understood the first part of the question. What do you mean 'all the details' of a transaction? In Bitcoin technology the transaction is a chunk o data with all information, so all the details of a transaction is the very transaction itself.
Osias Jota
<bitcoin-core>
How miner validates?
Mansi Goel
# How miner validates?

(Asked by: username_0 on 2018-03-06)

How miner validates each transaction? Does he have all the information of the transaction taking place between nodes?

Thank you.

**Tags:** bitcoin-core

> **Comments:**
> **username_1**: I'm not sure I understood the first part of the question. What do you mean 'all the details' of a transaction? In Bitcoin technology the transaction is a chunk o data with all information, so all the details of a transaction is the very transaction itself.  

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## 1 answers

### Answer by username_1 on 2018-03-07. Score: 0

Miners role is not to *validate* transactions, but to *confirm* them. Every node validate every transaction every time. A single invalid transaction would invalidate the entire blockchain.

In Bitcoin technology the transaction is collection of bytes. All the information about a transaction is the very transaction itself.

> **Comments:**
> **username_0**: For eg. If A wants to give 5 bitcoin (for an instance) to B and A has only 3 bitcoin with him. In this case how this invalid transaction would be invalidated by other nodes? And here another question arises how blockchain helps to prevent duplication of bitcoins?  And also if the transaction is validated by other nodes then why there is a need of miner to confirm those same transaction?  
> **username_1**: If A wants to spend more bitcoins he has, he will setup this invalid transaction in his computer. So he'll send that transaction to another computer running bitcoin. That computer will read the transaction received via the internet, see it's invalid (spend more than it can) and delete it from its memory.  No other node will accept or relay invalid transactions.  Your third question is the answer to the second one: miners confirm transactions to prevent duplication of spending. Read more here: https://bitcoin.stackexchange.com/questions/148/what-exactly-is-mining  

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