how blocks in blockchain are be consist with data??

[kasunrandil]

blocks are consist with transactions you all know. those details which includes in blocks are insert by minors or automatically?? details such as previous block hash , murkel tree anr etc?? could you explain me please ..??

[pooya87]

Each miner, or rather the mining pool, selects transactions from its own memory pool that pay the highest fee and inserts them into a new block which they are about to mine. They do this until the block weight reaches the maximum allowed value of 4 MB.
Then they update the block header that consists of merkle root hash computed using the transactions in that block, previous block header hash, version, time and nonce. Then they start mining the block.

You can read more about it here: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch10.asciidoc

[hZti]

The blocks including the data will after confirmation be stored on the blockchain. The blockchain contains all the transaction data since the first block and is about 330 GB at the moment. Your bitcoin wallet will connect to a node (basically a PC that has the full 330 GB of blockchain on it) and can check all the details and show it in your wallet. If you want you can also run a full node and share the transactions with other people.

[kasunrandil]

Each miner, or rather the mining pool, selects transactions from its own memory pool that pay the highest fee and inserts them into a new block which they are about to mine. They do this until the block weight reaches the maximum allowed value of 4 MB.
Then they update the block header that consists of merkle root hash computed using the transactions in that block, previous block header hash, version, time and nonce. Then they start mining the block.

You can read more about it here: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch10.asciidoc

each minor or the mining pool owns their own mempool??? i mean there are about 15000 nodes out there and it means that the same amount of memools are there?

[hZti]

Each miner, or rather the mining pool, selects transactions from its own memory pool that pay the highest fee and inserts them into a new block which they are about to mine. They do this until the block weight reaches the maximum allowed value of 4 MB.
Then they update the block header that consists of merkle root hash computed using the transactions in that block, previous block header hash, version, time and nonce. Then they start mining the block.

You can read more about it here: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch10.asciidoc

each minor or the mining pool owns their own mempool??? i mean there are about 15000 nodes out there and it means that the same amount of memools are there?

Yes but also no. Each node has their own mempool, but the mempools sysnconize each other. So you don't have to send your transaction to all the mempools. It is enough to be connected to a few nodes in the network and the rest of the nodes will then synchronize.

[kasunrandil]

The blocks including the data will after confirmation be stored on the blockchain. The blockchain contains all the transaction data since the first block and is about 330 GB at the moment. Your bitcoin wallet will connect to a node (basically a PC that has the full 330 GB of blockchain on it) and can check all the details and show it in your wallet. If you want you can also run a full node and share the transactions with other people.

oh. it is more than 420 gb at the moment .

[kasunrandil]

Each miner, or rather the mining pool, selects transactions from its own memory pool that pay the highest fee and inserts them into a new block which they are about to mine. They do this until the block weight reaches the maximum allowed value of 4 MB.
Then they update the block header that consists of merkle root hash computed using the transactions in that block, previous block header hash, version, time and nonce. Then they start mining the block.

You can read more about it here: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch10.asciidoc

each minor or the mining pool owns their own mempool??? i mean there are about 15000 nodes out there and it means that the same amount of memools are there?

Yes but also no. Each node has their own mempool, but the mempools sysnconize each other. So you don't have to send your transaction to all the mempools. It is enough to be connected to a few nodes in the network and the rest of the nodes will then synchronize.

ok then just explain me a bit , just think i submitted a transaction on the bitcoin blockchain. you all kniw that transaction goes to a mempool untill it is be confirmed and added to the block. i need to know that to the which mempool does it goes and are  all the minors able to see my pending transaction on the mempool?

[Upgrade00]

ok then just explain me a bit , just think i submitted a transaction on the bitcoin blockchain. you all kniw that transaction goes to a mempool untill it is be confirmed and added to the block. i need to know that to the which mempool does it goes and are  all the minors able to see my pending transaction on the mempool?

It doesn't go to any particular mempool. When you create and broadcast a transaction, nodes who act as verifiers, check through this transaction and add it to their mempool if it checks out, they can also broadcast this transaction with other nodes and it gets added to more mempools (after they do their checks of course).

Miners can check and chose which transaction to add to their blocks.

[franky1]

when someone makes a transaction. they relay that transaction to all their peers(other bitcoin software of other users)
all those other people check the transaction is trying to spend value that has not already been spent and other small checks to ensure validity.. and then keeps this unconfirmed transaction in a temporary list of a database called the mempool. each software has a mempool database of unconfirmed transactions.. these peers then relay it to their peers, who do their own checks and if valid put it in their mempool, so that the transaction reaches everyone via passing it around to everyone.

most people end up with a nearly similar list of unconfirmed transactions. but at this point its not important
some people may have been offline or had issues and may not have the transaction in their mempool if it was not passed to them at this stage. again not essential to have transaction in mempool, but it helps later stages

then the special users that run and manage mining (called mining pools) collate unconfirmed transactions from their copy of their mempool database, of unconfirmed transactions they received and validated.

most(pretty much all) have their own software programs that select the transactions they want to include, most of this is based on the fee of the transactions but pools can include code for selecting transactions for other reasons or ignoring some transactions for whatever reason.  its not normally(ever) where a person is manually selecting transactions using his eyes and brain and hands on a keyboard, as that is just not efficient.

the collated transactions are hashed together, this collated list of transactions hash is called the transaction merkle root hash
(one of the transactions included is one of their own which is a transaction that gives them a reward if their block is the one that becomes part of the blockchain, known as the coinbase transaction(block reward transaction))

they then with other details like the blockhash of the previous block(to chain blocks together), the merkle root hash and  some other details too . create a header (a small 80byte clump of data)

then they hash that header data using special devices known as asics(very fast and efficient devices that hash data trillions of times a second). to find a unique strong hash of that data that requires alot of time and effort to create this difficult hash.
once finding this difficult hash that meets the difficulty requirements of strength. this is deemed a solved block. and they relay this solved block to their peers which check that the data of transactions listed in the block result in the merkle of the block and the merkle, previous blockhash and other details calculate to the difficult block hash

any slight error in data would result in the hashes not matching the data, so it becomes easy to see if someone edited the data in the block relay stage.

by people keeping unconfirmed transactions before waiting for a solved block. they do not need to received a full 1-4mb of block data. they can just receive the blockheader portion of a block (the bit with all the calculated hashes)
which is very small amount of data compared to the full block of data
and then compare it and collate it with the transactions they already have. and just grab any missing transactions separately that were not sent to them at the unconfirmed transaction relay stage.
(basically it saves not having to receive the same transactions twice, thus saving bandwidth)

if all the data and hashes pass the checks the software accepts that block as a valid new block, it keeps it in a database of blocks (the blockchain database) and removes the transaction out of the unconfirmed mempool database.. and then the whole routine starts again on the next block unconfirmed transactions to get confirmed.

by everyone following the same check/validity rules they all end up keeping the same data as they are all keeping only valid blocks of transactions.
the blockhashs allow people to ask other peers what their blockhash is of their most latest block they have. without having to ask for a full block of data. so that they can see that their peers have the same lists as them

by storing the blocks in the blockchain database. new peers(without any/latest data) can ask for this full length data to catch up with the other users so that everyone is in sync