What is mean by accessibility?

Answer 1

Class access is the ability for any given class to access the functions of another class. Private access limits access to data and code just to the class that contains the private access modifier. The so-called "default" access grants private access, as well as access to any class in the same package. Protected access grants the same as "default" access, and also allows subclasses to access the code and data. Public access allows any class in any package to access the code and data.