Internal keywords in C #

For some large projects, usually composed of many DLL files, referencing these DLLs, you can access the DLL inside the class and the method inside the class.
For example, you write a log DLL, any project as long as the reference to this DLL can realize the function of logging, the DLL file program is an assembly.
If you log an assembly that is so defined:

namespaceLogerhelper {Internal classAA { Public voidBB () {return ""; }    }     Public classWrite { Public voidWritein (stringcontent) {            classx =NewAA ();        X.BB (); }    }}

When another project references this DLL, it can access:

New logerhelper.write (); X.writein ("");

But you can't access this.

New Logerhelper.aa (); x.bb ();

This is called, and can only be accessed in the assembly.

Internal keywords in C #