evaluation or simplification ?



Hello,

I have 

(%i1) listarith: false$
(%i2) x: [1,2]+p*[3,4];
(%o2)                          [3, 4] p + [1, 2]

When I do now

(%i3) ev(x, listarith: true);
(%o3)                         [3 p + 1, 4 p + 2]

is this evaluation or simplification ? Can someone please explain the notation?

Thanks
Volker van Nek