LOX is liquid oxygen, which is not a fuel, but an oxidizer. Starship is fueled by liquid methane. Methane can not be made from just water, you need a source of carbon. On Mars for example methane could be produced from CO2 in the atmosphere and water from ice.
It’s fueled by LOX which can be made from water, making it suitable for refueling anywhere we can find ice in the solar system.
LOX is liquid oxygen, which is not a fuel, but an oxidizer. Starship is fueled by liquid methane. Methane can not be made from just water, you need a source of carbon. On Mars for example methane could be produced from CO2 in the atmosphere and water from ice.