Schools that you know you will get into (based on assured admittance requirements) or schools that you know you have a very good chance of getting into (ie. SAT scores and GPA exceed requirements).
Schools that you feel like you have a decent chance of getting into, but it is not a guarantee (ie. your GPA and SAT scores are in the school’s average range). These schools might include your top choice school.
Schools where you may not quite meet the admissions standards and you may be taking chance by applying. Even if the school may be hard to get into, it is still good to try! Although your GPA or test scores may be lower than what they usually accept, other factors like community service, extracurricular activities, background, etc. may help you get accepted.