Eli5: how does a cord landline work when the power is out?

Question

Like the phones that have a special plug and everything, the cord one still work when the electricity is out and they don’t seem to have batteries in there, so how and why do they still work

In: 142

Answer 1

A subscriber loop in a “plain old telephone service” (POTS) system carries its own 48 volt DC power, supplied by a bank of batteries in the central office.