In Java, access modifiers and non-access modifiers are used to control the visibility and accessibility of classes, methods, and variables. Access modifiers define the scope of accessibility, while non-access modifiers define additional properties or behaviors of these elements.

Access modifiers are used to specify the level of accessibility of a class, method, or variable from different parts of a program. There are four access modifiers in Java: public, protected, private, and default. Public access modifier allows classes, methods, or variables to be accessed from anywhere in the program, while private access modifier restricts access to within the same class only. Protected access modifier allows access to the class itself, its subclasses, and classes in the same package, while default access modifier allows access to classes within the same package.

Non-access modifiers are used to define additional properties of classes, methods, or variables. There are several non-access modifiers in Java, including final, static, abstract, synchronized, transient, and volatile. Final modifier indicates that a variable cannot be changed once it is initialized, while static modifier indicates that a variable or method is shared among all instances of the class. Abstract modifier is used to create abstract classes or methods, while synchronized modifier is used to control access to shared resources in a multithreaded environment. Transient modifier is used to exclude a variable from being serialized, while volatile modifier is used to indicate that a variable may be modified by multiple threads.

In summary, access modifiers control the scope of accessibility, while non-access modifiers define additional properties or behaviors of classes, methods, or variables.