Thanks , I’m grateful!!!
2 Likes
I had a query regarding the previous section, I couldn’t understand the difference between the UTXO and the account model and which one is more beneficial? Also, I couldn’t understand how the transactions work in the account model. @ivan
1 Like
Hi @Parsh09, When I was trying to get more clarity on the UTXO vs account method, this article on medium from 2018 comparing the two gave a concrete example walkthrough: https://medium.com/@sunflora98/utxo-vs-account-balance-model-5e6470f4e0cf
It lays out that each method has its own benefits, with the decision on what might be “better” mainly being convenience vs privacy. Personally I’ve always found the account balance updates during a UTXO transaction alarming until the portion sent back to the sending account lands back in place.
1 Like
Hi everyone, i’m delighted to be a part of the IOT family. Hopefully, as time goes on I can participate on more and more things as my education progresses.
1 Like
UTXOs are just all the ‘incoming’ payments your wallet has. Until you send some money to another wallet, they remain as Unspent Transaction Outputs. Once you do send someone money, they all get added up by the network (and the total is shown to you on screen), and then if you have a total of 10 BTC in UTXOs and you send 2 to Bob, your wallet will send all 10 BTC out, 2 to Bob and 8 back to you. Every transaction must send out all UTXOs. It’s like you’re giving someone a £10 note and they give back the change. This means that it’s impossible to tell who received how much money in the transaction.
With an account model in Ethereum, every wallet shows the balance of their coins on the blockchain (I believe), rather than a collection of UTXOs. When a tx is made, the code is simply states -2 ETH* Parsh , +2 ETH* Bob. This occupies much less room than summing and sending all UTXOs.
It occupies less space, but anyone on the blockchain can see how much money a wallet is holding. They don’t know who the wallet belongs to, but I’m assuming people can identify that via other ways.
Edit: *corrected BTC to ETH
1 Like
Hello, how are you? Question, was that a typo when you stated -2 BTC Parsh, +2 BTC Bob? Did you mean -2 ETH, etc or am I missing something about a change in the Bitcoin platform. Just inquiring, Thanks. I’m still pretty new here. 
1 Like
Hiya, I’m very good, this course is amazing. How are you?
And yeah I meant -2/+2 ETH. Sorry, didn’t mean to confuse you, was just typing out the example and said BTC 
but nonetheless the point is the same - everyone has a balance and when a transaction happens, X get’s taken out of your account and added to mine.
Whereas with BTC whenever a transaction happens, all the UTXOs that you have coming into your account from others will be summed together (balance shown to you on screen) and then however much will be sent out to my wallet (and it becomes one of my UTXOs) and the rest get’s sent back to you. That’s because your entire account get’s sent out in the BTC network, with whatever you want to send to the recipient and the ‘change’ back to you; this makes it more private because you can’t tell who’s who and what’s what.
Hope that helps 
1 Like
It is really awesome… Thanks for all the input.
I have a question:
Where is this excel sheet which IVAN is talking about. I mean the price table for which interaction costs how much GAS ? I found a few… But which one is the real ? Any prooved source ?
Cheers MChoeti
So far, so good. What I enjoy the most is the fact that Ivan is very structured and clear, the fact that he translates everything in his own words with simple sketching for me is the best way to understand things. There’s somewhere a saying that emphasizes that only by understanding the concepts very well, are you able to explain it simple. Thank you Ivan, keep up the good work! @ivan
1 Like
So far I have really enjoyed learning here. Thank you so much Ivan and team for this academy.
1 Like
Hi, just wanted to double check one thing that im not sure about which is Gas. Gas is basically fees on Ethereum blockchain, right? and the fees charged will depend on how much the miners will charge for the execution of a smart contract? Correct me if im wrong on this,please!
1 Like
Indeed sir, Gas is the term used on the amount of wei that you will have to pay to the network so a miner can append your transaction into the blockchain.
If you have any more questions, please let us know so we can help you! 
Carlos Z.
Hi guys, can someone give an in depth explanation about the link between gas and ether ?
I want to make sure that I have a deep understanding.
Thank You!
1 Like
check out this link https://medium.com/sunnya97/understanding-ether-vs-gas-82ce2f1dc560#:~:text=Ether%20is%20a%20currency.,cost%20of%20using%20the%20system.
Happy learning
A Sebhatu
2 Likes
Hello Academy team, please check out link #3 it isn’t working
Cheers
1 Like
Hi guys, just finished the Ethereum course, very interesting but still getting my head around how it can deal with the complexity of some smart contracts and the potential need of a 3rd party (as below). Any thoughts would be much appreciated!
-
Who verifies that all conditions in a smart contract are truly met when external documentation is required? In Ivan’s kids example where the money is paid out if certain grades are exceeded, how can this be confirmed without a third party? He mentions ‘fetching grades from the school’. Who would do this and what’s to stop people faking documentation to trick the system into releasing the funds?
-
Does this limit how complex a smart contract can be when such information is required? I’m struggling to understand how consensus would be reached in a timely manner in many scenarios like this.
4 Likes
I have been hesitant to get back into playing around with Dapps because of this. 
1 Like
@filip
Quick question: If ETH is account based only and more transactions can be completed should this not make the mining fees lower as currently on most ethereum platforms the fees are ridiculous…
1 Like