This differs a lot by country and customer. For example, in Germany, without a fixed income, you’ll usually not get access to an overdraft loan.

In the US, overdraft is generally considered a very bad thing (almost worse than the idea of credit to Germans!) and a failure of the accountholder to “balance their (figurative, today) checkbook”, and the idea of an overdraft limit as a line of credit with a defined interest rate does not exist at all.