The idea of eugenics was that of “selective breeding” amongst humans which focuses on weeding out “undesirable” qualities within mankind. In history, scientists attempting to alter gene pools with eugenics have excluded groups deemed as less than or inferior and nurtured up groups they thought of as superior.
(Some history)
Unfortunately, in eugenics (United States) the victims of eugenics were frequently disabled, impoverished, ill (mentally), people of color, and women. (Although men did fall subject to sterilization, disproportionately it affected women of color (Natives, Blacks, Hispanics, etc)
Note: this is likely why eugenics is associated with racist/discriminatory movements. There was other eugenic events like Nazi eugenics that contributed as well.
Conclusion: the idea of eugenics is to breed/weed out undesirable (genetic) traits
Apologies if anything is incorrect.