What's the difference between overdraft and advance?

Simply put:

Overdraft: it means taking all the money. For example, if you take all the money from the bank, it's called overdraft.

Advance: not all, that is to say, if you work in a certain unit, you can advance the living expenses to the company. The money you advance must not exceed your labor income, which is generally a few tens of percent, which is relatively small.

Overdraft means withdrawing cash in full.

Advance payment is a small withdrawal.