Confusion with setfill() and fill().....In CPP

Question

In CPP I have seen the use of both and know why they are used but why is setfill() (Iomanip class function) used without creating an object (and how can you use a function without declaring the object first?) while for using the fill() (iostream class function) we have to use the predefined iostream objects like cout......?
cout<<fill(10)<<"Hello"<<endl;
cout.setfill(10);
cout<<"Hello"<<endl;