Answer 1

In Java, you have got something called access modifier, which specifies accessibility of class, methods and variables. There is four access modifier in Java namely public, private, protected and the default access modifier, also known as package level modifier.
The difference between these access modifier comes in their ability to restrict access to a class, method or variables, public is the least restrictive access modifier while private is the most restrictive access modifier, package and protected lies in between.

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