Miranda rights are only supposed to be read for you. They are only applicable is if you are in custody and the police want to ask you incriminating questions about your case. So it’s a two-prong test the first prong is are you in custody so are you arrested are you in a position where you can’t you are not free to leave from police presence. If the answer is yes then you’re in custody the second prong is are the police asking you questions about your criminal case. If so, they must read you your Miranda rights. If not, they don’t have to so for example if you are arrested and the police ask you what is your full name well that is not an incriminating question so you don’t have to have your Miranda rights read to you. However, if you are arrested and the police say why did you do this crime guess what they need to read you your Miranda rights before you answer that question so that is when and why it’s important.