ACCESS MODIFIERS IN .NET

public

This makes the member visible globally

Eg. class Gremlin { public Gremlin spawn() { return new Gremlin(); } }

protected

This makes the member visible to the current class and to child classes. Protected members are only accessible in the same class or through inherited classes.

Eg. class ParentClass { protected int valueA; }
class ChildClass { public void doSomething() { valueA = 3; } }

private

This makes the member visible only to the current class.

Eg. class MyCollection { private int lastIndex; }

internal / Friend

This makes the member visible within the same assembly.

Eg. internal class ProprietaryStuff { }

protected internal / Protected Friend

A combination of protected and internal. This makes the member visible within the same assembly and also makes the member visible to an inheriting class. An inheriting class does not need to be in the same assembly to access the member.