Winnie has 7 soccer trophies she wants to display in an array. how many different arrays are possible? explain

There's 7 possibles ways to arrange them originally, then after that one is placed then there are 6 possible ways5,040 I think because 7•6•5•4•3•2•1=5040
and why 
there's 7 possibles ways to arrange them originally, then after that one is placed then there are 6 possible ways

Cdoes not have two variables