Define ‘Double-Spending’ and Explain How the Blockchain Structure Prevents It

Double-spending is the malicious act of successfully using the same digital currency unit more than once. The Bitcoin blockchain prevents this by recording every transaction in a public, immutable ledger.

Once a transaction is included in a block and that block is followed by subsequent blocks (confirmations), the transaction is considered final. The Proof-of-Work mechanism and the chain of blocks make it computationally infeasible to reverse a confirmed transaction and spend the coins again.