hi everyone,
I can’t understund how multiple output transaction can be created.
(I ignore fees for now)
e.g.
So I have 4 UTXO (0.2, 0.3, 0.5, 0.9) assigned to my wallet.
I know that when I transfer e.g. 0.6 to someone, then two output will be created because the rest of the value transfered will be assigned back to my wallet (0.9-0.6 and 0.3 back to me). In that case I created a two UTXO.
But how I can create more than two UTXO in a single transaction?
like there:
The wallet does this for you in the background. If you want to have more control you would have to use a more advanced wallet or create a raw transaction yourself. You can check our Bitcoin programing course to learn how to do the latter. 
Hi Ivan and all,
I am still learning basics of bitcoin, but with so-far what I understood is, miner’s do have an incentive to earn money to complete proof-of-work with which the blocks are added to the block-chain.
Question is, what will happen when all possible bitcoins will be mined? What will be incentive for anyone to continue supporting proof-of-work?
Is it going to be a feasible solution post 2140 AD?
By that time its expected bitcoin will be valuable enough for the fees to compensate the block reward to miners.
There could also be a hardfork to increase the supply beyond 21 million, no one knows for sure.
SVP = Simple Payment Verification 
That is such a valuable answer and this course has helped me in understanding it better.
Thank you so much!
If we could use more visual examples for some of the function explanations, I think it would help out tremendously. At times when the explanations are getting a bit more complex, it would be easier to maybe have a short power point of some kind, as a visual example or a summary of the lesson. Regardless this Blockchain chapter has been extremely insightful.
Thank you!
Nanx0
I just realized something while studying a block in a block explorer:
Not all bitcoin in the coinbase transaction are newly minted. Since the fees are also included in the coinbase transaction, the bitcoin deriving from the fees are effectively old bitcoin that are being “washed” of their history.
It probably has no greater significance, I just found i curious. Maybe someone else could elaborate
Its true, you could potentially pay a high fee to the miner that you know and get clean BTC from that. Given that you are lucky that the miner you are collaborating with wins the block. 
Question
I am trying to grasp the concept of UTXO. Is this statement true?:
At any given point in time the sum of all UTXOs equals the bitcoin money supply.
(December, 2020: UTXO set = approx. 18 560 000 BTC)
It should yes. Also the sum of all UTXOs you own is the balance in your wallet.
I have a question about the cold storage wallet.
When and if someone looses their cold storage wallet, is all the information on the wallet lost ?
How is it possible to retrieve all the data using your 12/24 words to key into the new wallet ?
Was the data stored in the cold storage wallet, or partially on Blockchain, SPV or something ?
Because when you use the 12/24 word to enable a new wallet you get all the data back. So if the wallet was lost obviously the data was somewhere else on the network. So please if anyone has knowledge of this Id appreciate your info on this.
Thank you Much Love & Respects. 
There is no coins in your wallet everything is stored on the blockchain, your keys are the means of accessing that data.
The 12/24 word mnemonic keys have a numerical mapping that in its entirety form a private key. Words are used so that they are easier to remember than numbers. For example:
| dog | 001 |
| cat | 010 |
| mouse | 100 |
And you have a mnemonic seed: cat dog mouse that means your private key is 010001100. Mnemonic codes been introduced in BIP39
Wallets that support mnemonic codes are usually also HD (hierarchical deterministic) wallets, meaning that they derive multiple private keys from a single master key (fancy name for the root private key) based on a derivation path described in BIP32.
This is why you only have to backup the root key because all your keys are derived from said key
Alko,
Ya totally detailed answer, much appreciated. That makes sense about it all stored on blockchain.
The Master key is the way its done, so cool ( like you say fancy name for private key
Overall a really great system. I just needed to wrap my head round that. Once again thank you for your prompt answer & all your likes.
Much Love & Respects
Can someone help me with this one:
Is this negligible? Does it spread so rapidly that the risk of this is near impossible - Or do I understand it wrong completely?
Cheers
Each node will verify the tx independently and will only propagate further txs that are valid according to its rules. In case a tx is sent directly to the miner and the miner puts is in the block, nodes will also verify all txs in a block they received in that case if there is an invalid tx in a block they will reject the entire block.
Hi Guys! Could you please help me understand in layman’s terms How does a growing mempool effect transaction fees?
eventually the Tx which are not confirmed will be added in the subsequent block right? and why would someone cancel the transaction and resubmit it with higher fees, what value it will provide to the sender? he is losing more money in fees
Ohh, I saw this after I read your homework.
Basically it will raze fees in the network because people will want their tx to be processed asap and will pay more to get it processed faster.
Its a supply and demand situation, when the block space is scarce, the fees will increase.
You could also wait for the fees to decrease but in case of a bull run like it happened a few years ago the mempool was so full that people were waiting for days for their tx to go trough. Now if you want to sell before the dump its better to pay more in fees than be to late right?
Ohh Yes! that definitely make sense. Much appreciated!
so it really comes to number of Tx pending in the mempool and the urgency of confirming the transaction.
in some cases, it make more sense to pay standard or lower fee to transfer the bitcoin or pay higher fee when their is network congestion and want to confirm the transaction immediately.
Hey Guys! maybe a dumb question - what value nodes get to run the software and maintain the public ledger?
