Are you in school? (let's assume you are for the moment) Do you have classmates? How many? And how many in the whole school? (let's use 1000)
Would you want to define a single variable for everyone's name, then another for address, city, current class, grades so far..... That's 1000 distinct variables for the name. Another 1000 for the addresses. Another 1000...
I wouldn't. But one variable for the name, one for the city, etc, as an array and you have all the students in the array and you can get the information easily from just a few variables.
public class GrossmontBank
//class variables (global - accessible throughout this class)
//scanner object to be used throughout
private static Scanner input = new Scanner(System.in);