Do we now have to go looking all transactions of Alice saved on blocks and to calculate her steadiness
No one apart from Alice cares about her steadiness. That is as a result of Bitcoin is money, not a checking account. While you hand over a $10 banknote to a shopkeeper, they do not need to understand how a lot complete money you’ve in your pockets, they simply take a look at the $10 to see whether it is real. Bitcoin doesn’t preserve monitor of steadiness per account holder – there aren’t any accounts, no individuals, no balances within the Bitcoin community or blockchain.
Bitcoin works on the premise of preserving monitor of Unspent Transaction Outputs (UTXOs). A UTXO is roughly equal to a banknote or coin. When somebody spends a UTXO, all different nodes test that the UTXO exists and hasn’t been spent already.
You’ll be able to create a listing of UTXOs by studying the blockchain from the beginning as soon as.
A Bitcoin pockets akin to Bitcoin core could present strategies of wanting on the knowledge in its copy of the blockchain. For instance Bitcoin core has an RPC API together with features akin to getreceivedbyaddress – which usually solely works by yourself addresses, not different individuals’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 knowledge.
The Bitcoin community protocols permit any new node, akin to a pockets, to find just a few different nodes and to request from them copies of blockchain knowledge, piece by piece.
Usually talking, deal with balances are of no curiosity in any way. They play no half in the best way Bitcoin operates. You may rummage by means of your pockets and rainy-day coin-jar to jot down down the entire sum of money you discover however nobody else actually cares.
