Ideas in this flowchart

• The Bitcoin blockchain records transactions in chronological order.
• The blockchain is a chronological chain of blocks.
• Each block contains transactions.
• The transactions in a block occurred around the same time.
• The sequence records balances associated with Bitcoin addresses.
• The recorded balances are associated with Bitcoin addresses.
• The sequence records identifying information associated with Bitcoin addresses.
• A later attempt may spend an already used balance.
• The balance involved in the attempt has already been used.
• The later attempt is identifiable as illegitimate.
• A payment remains pending.
• Miners place the payment in a block.
• The transaction becomes permanently recorded.
• The transaction becomes confirmed.
• The confirmed transaction is effectively irreversible.