Double spending refers to the risk of a digital currency being spent more than once. It occurs when someone tries to make two transactions with the same amount of cryptocurrency simultaneously. This is a problem unique to digital currencies because they can be easily copied or replicated.To prevent double spending, most cryptocurrencies use a decentralized ledger called a blockchain. When a transaction is made, it is recorded on multiple computers (nodes) in the network. Before a transaction is confirmed, other nodes verify that the sending address has enough balance and hasn’t previously spent the same coins.If a double spending attempt is detected, the network rejects one of the conflicting transactions. This helps maintain the integrity of the currency and ensures that each coin can only be spent once. Overall, preventing double spending is crucial for maintaining trust and reliability in digital transactions.