The scale is likely the Kinsey scale. A 0-6 scale of sexuality. Zero is completely straight and six is completely gay.
Most people find themselves somewhere in the middle, even if they don’t admit it.
I’m somewhere in the range of 1–1.5
I’m firmly attracted to the opposite gender, but might make an exception if the person had a personality that was super compatible with my own. But it’s not something I’m going to seek out.