besides grades & test scores
It depends on the school. Grades, test scores, school sees you as making a positive contribution on campus. Ability to pay matters at many schools.
my son was accepted to a small liberal arts college in Maine. He had a great interview on campus. I think that helped him. High test scores and good grades.
You are admitted because the admissions tam believes that you can be successful there and that your presence will fill some percieved need in the campus community.
It all depends on the school, what they specifically look for, who reads your application, and how you express your desires and passions, whether they’re academic or otherwise. I talked to the admissions officer who had sent me my acceptance, and she said that an essay I wrote about being involved in music in addition to academics was something that stood out in my application.