Hi i am just a newbie in this thing but there is something i can not understand if blockchain keeps every transaction in it and creating a new block to blockchain takes so much time then doesn't it supposed take long time to confirm a transaction that is sent from A to B?


Yes, the system is designed in a way that you should expect a new block to be mined every 10 minutes, which is what is needed for a new transaction to confirm. As more blocks are mined on the top if it, the transaction gets more and more "confirmations". Each user decides how many confirmations are required for the transaction to be considered "safely completed".

Although it should take roughly 10 minutes to create one confirmation, due the nature of the process, it can be much faster (think tens of seconds) or much slower (think more than 1 hour). So definitely, in some cases, you may need to wait a long time before you get the number of confirmations you want. Another factor here is the number of transactions that are currently waiting to be confirmed. If there are many such transactions, your transaction may not make it into the very next block, thus prolonging the delay even more.

This is the reason for many different technologies to emerge. You can see many altcoins that change the parameters to lower the time needed for the successful "completion" of the transaction. But even on Bitcoin, you can see technologies like Lightning Network to emerge that promise very fast completion times.

  • What i read in bitcoin wiki the process of creating a new block for each transaction is the mining itself am i wrong? if so the process of mining getting harder as long as block chain gets bigger how could it be less than a hour or up to couple of hours? @wapac – Deniz Gokce Jul 31 '17 at 10:43
  • Each block has 1 or more transactions and usually it is much more - up to a few thousands. Check out currently last block for example - blockchain.info/block/… - it contains 2118 transactions. So every 10 minutes, you can get a few thousands of transactions confirmed. The mining process is getting harder (or easier) during so called difficulty adjustment - see bitcoin.stackexchange.com/questions/5838/… for explanation and bitcoinwisdom.com/bitcoin/difficulty for history. – Wapac Jul 31 '17 at 10:53
  • So one block consists of multiple transactions like 2000 or more, how it is calculated if there is thousands of them then one miner could be mining A transaction in their thousands of stack and other miner could mining that the same transaction in their own stack? The last thing i want to ask is if a miner creates a new block consisting thousands of transactions then does it notify all the other network nodes to stop what working on those stack of all thousands of transactions is that true? @wapac – Deniz Gokce Jul 31 '17 at 11:48
  • Yes, each miner mines its own unique block and selects transactions that will be included. If it finds the solution for that block, it propagates it to the network and other miners will stop their work and start mining new block on the top of the block they received. But of course, they have to reevaluate which transactions they can include because that could be change due to the new block. – Wapac Jul 31 '17 at 12:19

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