What is the sabbath mode?

Answer 1

Observant Jews prepare all the food for the Sabbath on Friday before sunset, then store it for sabbath consumption. Judaism forbids initiating cooking on the Sabbath, but using the Sabbath Cooking mode, you can use the oven to keep food hot from Friday to Saturday. Also, it shuts off the light that turns on when you open the oven, as Judaism also forbids initiating or ending an electric current on the Sabbath.

Answer 2

During Shabbat, religiously observant Jews do not turn electric devices on or off. As a result, they will leave ovens on at low temps for the whole of Shabbat which allows them to warm food.

Modern appliances such as ovens, are programmed to automatically turn off after a certain number of hours. Sabbath mode on ovens disables the automatic turn off, they also disable the automatic light that turns on when you open a fridge.