Access Modifiers (C# Programming Guide)

public

The type or member can be accessed by any other code in the same assembly or another assembly that references it.

private

The type or member can be accessed only by code in the same class or struct.

protected

The type or member can be accessed only by code in the same class or struct, or in a class that is derived from that class.

internal

The type or member can be accessed by any code in the same assembly, but not from another assembly.

protected internal

The type or member can be accessed by any code in the assembly in which it is declared, or from within a derived class in another assembly. Access from another assembly must take place within a class declaration that derives from the class in which the protected internal element is declared, and it must take place through an instance of the derived class type.

An enum has default modifier as public

A class has default modifiers as Internal . It can declare members (methods etc) with following access modifiers:
public
internal
private
protected internal

An interface has default modifier as public

A struct has default modifier as Internal and it can declare its members (methods etc) with following access modifiers:
public
internal
private

A methods, fields, and properties has default access modifier as "Private" if no modifier is specified.

What's New in ASP.NET 4.5 and Visual Studio 11 Beta

http://www.asp.net/vnext/overview/whitepapers/whats-new

http://www.west-wind.com/weblog/posts/2012/Mar/13/NET-45-is-an-inplace-replacement-for-NET-40