NOTE P69 1. Constant identifiers are by convention, capitalized. A final variable can be declared without initializing it immediately, For example,...

I really do not understand the concept of the number two and three. Can you please help me?

NOTEP691. Constant identifiers are by convention, capitalized.2. A final variable can be declared without initializing it immediately, For example,final double TAX_RATE;if (< some condition > >TAX_RATE = 0.08;elseTAX_RATE = 0.0;// TAX RATE can be given a value just once:, its value is final!3. A common use for a constant is as an array bound. For example,final int MAXSTUDENTS - 25;int classList - new int [MAXSTUDENTS] ;4. Using constants makes it easier to revise code. Just a single change in the final dec-laration need be made, rather than having to change every occurrence of a value.OPERATORSArithmetic OperatorsOperatorMeaningExampleaddition3 + x+