There are different access modifiers available in C#.Net.
Public
Access to property/method is public.
Private
Access to property/method is only restricted to the class in which it is defined.
Internal
Property/Method is accessible in whole project but not accessible in other project.
Protected
Own class and derived class can access it.
Protected Internal
Property/Method can be accessible in project which is inherited from the project (in which protected internal properties mentioned.)