We can split one part of a class in one file and the other
part in some other file using the partial keyword. The
compiler merges these partial classes spread across one or
more source files into a single compiled class at the time
of compilation .

we can declare more than one class of same in a Namespace
through partial keyword.
  Advantage->
    we can use only one object to intialize it.then through
that object we can their member.