Academic Safety: You know for certain that you will be admitted because the institution posts the minimum requirements for guaranteed admission right on its website and/or your high school has years of data that demonstrates that students like you always are admitted.
Financial Safety: You can afford the Cost of Attendance (COA) without any aid other than Federally determined (FAFSA) aid, and/or aid that you are guaranteed by your state because of your grades and exam scores, and/or aid that you are guaranteed by that college/university based on your grades and exam scores.
Rock-Solid Safety: An institution that is both Academically and Financially safe. If that place also offers your major, and is a place that you will be happy to attend if all else goes wrong during your application process, then congratulations! You have found your True Safety.
The ONLY institution that you should fall in love with is your True Safety. You need to like the rest of them, but since they aren't certain, do your best to limit the amount of emotion that you invest in them. And, if you can't find a True Safety, or at least a couple of decent Rock-Solid Safeties, then be sure to come up with a Plan B in case you don't get in anywhere that you can afford. Please, please, please, don't set yourself up to be the author of one of next April's "I didn't get in anywhere I can afford to attend, what do I do now?" threads.