Do we have now to go looking all transactions of Alice saved on blocks and to calculate her steadiness
No person apart from Alice cares about her steadiness. That is as a result of Bitcoin is money, not a checking account. Whenever you hand over a $10 banknote to a shopkeeper, they do not need to know the way a lot complete money you have got in your pockets, they only take a look at the $10 to see whether it is real. Bitcoin doesn’t maintain observe of steadiness per account holder – there are not any accounts, no folks, no balances within the Bitcoin community or blockchain.
Bitcoin works on the premise of maintaining observe of Unspent Transaction Outputs (UTXOs). A UTXO is roughly equal to a banknote or coin. When somebody spends a UTXO, all different nodes verify that the UTXO exists and hasn’t been spent already.
You may create a listing of UTXOs by studying the blockchain from the beginning as soon as.
A Bitcoin pockets equivalent to Bitcoin core could present strategies of trying on the information in its copy of the blockchain. For instance Bitcoin core has an RPC API together with capabilities equivalent to getreceivedbyaddress – which usually solely works by yourself addresses, not different folks’s.
there are instruments to know the steadiness of an adress. However my query is how this instruments works ? How they request the blockchain?
They’ll use the Bitcoin community protocol to gather their very own copy of the blockchain, index it after which carry out their very own evaluation of that information.
The Bitcoin community protocols permit any new node, equivalent to a pockets, to find a couple of different nodes and to request from them copies of blockchain information, piece by piece.
Usually talking, tackle balances are of no curiosity in any way. They play no half in the way in which Bitcoin operates. You may rummage by way of your pockets and rainy-day coin-jar to jot down down the entire sum of money you discover however nobody else actually cares.
