College question-Getting into nursing school

When I look online at nursing schools at universities, they want a specific GPA. Now, is that your high school GPA? Because my mom told me that when you get into university, you're not in there nursing program until you're done with your pre requisite classes and then you apply for their nursing school. So do they look at your high school GPA or your college GPA or both? I'm so confused, lol. Someone help me and explain this to me.