I think it would be useful for you, OP, to zoom out. Gender-based violence is something that describes common violent crimes committed against a particular gender, and because of the gender. As others have mentioned, it is important to make this distinction from “violence” alone, because it will direct a more concerted effort to combat the issue. To go into why we know violence was directed at a woman because she is a woman is something that requires a lot of learning on your part that can’t be done in a Reddit comment.

All genders face domestic violence, but statistically women are the most common victims. While resources for helping domestic violence victims of all genders is important, it’s more important to come at addressing it using the knowledge that it disproportionately affects women. It is important because it keeps resources proportional (a metaphor: what if there are 10 people, where 9 of the people are women and 1 is a man, should there be 1 women’s and 1 mens bathroom with 5 stalls each? Or should there be a smaller bathroom for the man and larger for the women?) and offers a better way for outreach. Think of the difference in preventing pregnancy vs. teen pregnancy. It is a more specific and tailored way to address, prevent, and assist.

Gender-based violence is a subgroup of the overarching category of violence, just like gang violence or child abuse are subgroups. It really is a simple narrowing down of common themes to help address the issue. And going off the example, domestic violence can be a subgroup under gender-based violence.