What is this blue card that I received for driving when I was in high school ?

Tomorrow I'm going to the NJ Motor Vehicle Commission for a replacement/duplicate because I lost my blue card that I received when I was back in high school and I can't do my next practice driving nor do my road test next month with out it.It's a small blue card with my grade on it ( a 94) with the advertisement label NJ Motor Vehicle Commission.I just want to know what it is called just in case when I enter the building the people would know what I'm talking about and so they won't give me a hard time.Is it some kind of permit? I'm 18 years old by the way.