Candle on earth vs candle in space

To elaborate on this, hot air goes up. But in zero gravity, what's up? So the CO2-laced air accumulates around the candle and oxygen keeps being pulled and if the system is perfectly undisturbed, the candle'll burn itself out because it eats all the oxygen around it.

I assume they mean zero/micro-gravity.

You can light it with gas, but fire needs oxygen