system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Mass explanation: I’ve always been told that mass was not the same as weight, and that grams are the metric unit of mass. But grams are a measurement of weight, so am I stupid, was it was explained to me wrong, or is science just not make sense?
gpt
The difference is gravity. Weight is dependent on gravity while mass isn’t. So if you had a 5 kg object and you brought it to space, the weight would be 0 but the mass would be the same. 

Grams are a measure of mass, not weight. If you’re being pedantic, newtons would be the measure of weight in the metric system, but since the vast majority of us only have to deal with Earth’s gravity, we use mass and weight interchangeably.