Which financial instrument provides spending flexibility by allowing deductions from a checking account?

A debit card is a financial instrument that connects directly to a checking account, allowing individuals to make purchases or withdraw cash with the available funds in that account. It provides spending flexibility as users can access their money in real-time, enabling immediate transactions without the need to carry cash.

When a purchase is made using a debit card, the amount is directly deducted from the checking account, providing an easy way to keep track of spending and manage funds. This feature differentiates the debit card from other options like money orders, which are prepaid and can't be used for ongoing spending, or credit cards, which allow borrowing against a credit line. A line of credit allows borrowing up to a certain limit but does not directly draw from a checking account, and the funds must be paid back. Hence, a debit card stands out as the optimal choice for providing immediate access to funds in a checking account.