Bank of America Overdraft Question

On the site it says "This summer, your personal checking account will automatically be set to the Standard Overdraft Setting. With this setting, your ATM transactions and everyday (non-recurring) debit card transactions will be declined when you don't have enough money in your checking account or linked Overdraft Protection Account." That means a transaction will just be denied if I don't have enough money in my checking account right? I just don't want any overdraft fees, and I like only having around $100 in my checkings at a time because I like putting the rest in my rent money account. Just want to verify that I understand this correctly.