Access Modifiers:

These are used to provide restriction to the members of a class or class to access in same class or in derived class in same Assembly or different Assembly etc.
 

.NET supports Five types of Access Modifiers

1.     private: Private Members are accessible only within the same class

2.     protected: Protected Members are accessible within the same class and also in the derived class, derived class might be in same assembly or in different assembly

3.     internal: Internal Members are accessible in any class within the same assembly but not accessible in any class outside the assembly

4.     Protected internal: This is combination of both Protected and Internal i.e. protectedinternal members are accessible in any class with in the same assembly and also from the derived classes outside the assembly, but not accessible from the Non-Derived classes outside the assembly

5.     Public: Public members are accessible in any class in any assembly

We can summaries all these in a table like given below, in this table ‘×’ represents Not Accessible and  √  represents Accessible