An overdraft is a short-term credit linked to an account. It is set up in advance and used automatically: when there are insufficient funds, the payment is made from the limit, and incoming funds are directed to repay the debt incurred.
The main difference from a regular loan is the absence of a payment schedule and fixed term. The debt is repaid as funds arrive, and interest is charged only on the amount actually used and only for the days of use.
This same feature creates a risk. An overdraft is inconspicuous in daily operations, and the borrower easily stops distinguishing between their own and borrowed funds, perceiving the limit as part of the available balance. Debt in such a mode can exist permanently, and interest can accrue for months.
When connecting, it is worth clarifying the annual interest rate, the order of interest accrual, the presence of a commission for limit maintenance, and the maximum period of continuous debt. To maintain control, it is useful to focus on your own funds rather than the available balance.