arno/bitcoinbook
1
0
Fork 0
mirror of https://github.com/bitcoinbook/bitcoinbook synced 2025-02-17 01:52:09 +00:00
Code Issues Releases Wiki Activity

Made changes to ch05.asciidoc

Browse Source
This commit is contained in:
myarbrough@oreilly.com 2014-11-18 07:49:06 -08:00
parent 4f89209629
commit 021fc365a5
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
ch05.asciidoc
View File

@ -63,13 +63,13 @@ A transaction contains a number of fields, as shown in <<tx_data_structure>>.
.Transaction Locktime
****
((("locktime")))((("transactions","locktime")))Locktime defines the earliest time that a transaction can be added to the block chain. It is set to zero in most transactions to indicate immediate execution. If locktime is nonzero and below 500 million, it is interpreted as a block height, meaning the transaction is not included in the blockchain prior to the specified block height. If it is above 500 million, it is interpreted as a Unix Epoch timestamp (seconds since Jan-1-1970) and the transaction is not included in the blockchain prior to the specified time. The use of locktime is equivalent to postdating a paper check.
((("locktime")))((("transactions","locktime")))Locktime defines the earliest time that a transaction can be added to the block chain. It is set to zero in most transactions to indicate immediate execution. If locktime is nonzero and below 500 million, it is interpreted as a block height, meaning the transaction is not included in the block chain prior to the specified block height. If it is above 500 million, it is interpreted as a Unix Epoch timestamp (seconds since Jan-1-1970) and the transaction is not included in the block chain prior to the specified time. The use of locktime is equivalent to postdating a paper check.
****
[[tx_inputs_outputs]]
=== Transaction Outputs and Inputs
((("transactions","unspent transaction output")))((("unspent transaction output (UTXO)")))The fundamental building block of a bitcoin transaction is an _unspent transaction output_, or UTXO. UTXO are indivisible chunks of bitcoin currency locked to a specific owner, recorded on the blockchain, and recognized as currency units by the entire network. The bitcoin network tracks all available (unspent) UTXO currently numbering in the millions. Whenever a user receives bitcoin, that amount is recorded within the blockchain as a UTXO. Thus, a user's bitcoin may be scattered as UTXO amongst hundreds of transactions and hundreds of blocks. In effect, there is no such thing as a stored balance of a bitcoin address or account; there are only scattered UTXO, locked to specific owners. The concept of a user's bitcoin balance is a derived construct created by the wallet application. The wallet calculates the user's balance by scanning the blockchain and aggregating all UTXO belonging to that user.
((("transactions","unspent transaction output")))((("unspent transaction output (UTXO)")))The fundamental building block of a bitcoin transaction is an _unspent transaction output_, or UTXO. UTXO are indivisible chunks of bitcoin currency locked to a specific owner, recorded on the blockchain, and recognized as currency units by the entire network. The bitcoin network tracks all available (unspent) UTXO currently numbering in the millions. Whenever a user receives bitcoin, that amount is recorded within the block chain as a UTXO. Thus, a user's bitcoin might be scattered as UTXO amongst hundreds of transactions and hundreds of blocks. In effect, there is no such thing as a stored balance of a bitcoin address or account; there are only scattered UTXO, locked to specific owners. The concept of a user's bitcoin balance is a derived construct created by the wallet application. The wallet calculates the user's balance by scanning the blockchain and aggregating all UTXO belonging to that user.
[TIP]
====