我有个问题要请教？

Question

type
  Tnoisydeath =class
      .......end;
  procedure Tform1.Button1Click(sender:Tobject);
   var
    Noisydeath:Tnoisydeath;
      Begin
        NoisyDeath:=Tnoisydeath.create; // 为什么Tnoisydeath.create要赋给 NoisyDeath有什么作用呢？请给我个例子说明或者源代码。
        try
         ...
        finally
         noisydeath.free;
        end;
   end;
   procedure Tform1.Button2Click(sender:Tobject);
   var
     NoisyDeat:TnoisyDeath;
      Grim:ImtReaper;
   begin
     NoisyDeath:=TNoisyDeath.Create;
     Grim:=TmtReaper.Create(NoisyDeath);
     ....
  end;
end.