Not necessarily! I use a credit union and overdraft protection with them means thats if you are going to over draft by less than $50, they can take the amount from your savings to use for the charge. They then send a text that your overdraft took money from your savings and that future overdrafts would be blocked unless you call them to unlock overdraft protection again. (You can do this in the app as well).

My CU doesnt ever allow overdrafts otherwise. They do offer a credit card with no fees that they recommend for people who travel and might end up in situations where they need more money than planned or their debit card doesnt go through.