Meaning of negative/positive instances for scale_pos_weight

I want to understand what negative/positive instances in the documentation mean for the use of scale_pos_weight. Some resources online said “negative instances” mean the class with smaller number of instance while others said it simply means the class with label = 0. Which one is correct?
Also, for the case where samples are weighted, I assume sum(negative instances) / sum(positive instances) would mean “weighted instances”?
Ka Wa

Here, the negative instances are the ones with label = 0.

Yes, this is a typical value for scale_pos_weight. From