Many financial institutions offer services to help clients avoid overdrawing the money in their accounts. However, these services are often accompanied by fees and other charges.
Overdraft protection provides for a transfer of funds into your account if you draw more than your current balance. Bounce protection is where the bank covers charges to your account over your balance. Typically a fee is charged each time you exceed your account balance. You can learn more about both of these from the Banking Department here.
The Federal Reserve Board offers a guide, Protecting Yourself from Overdraft and Bounced-Check Fees, which is also available in Spanish.