to have an effect / no effect on sb/sth :
The rain didn't make much difference to the game.
Your age shouldn't make any difference to whether you get the job or not.
Changing schools made a big difference to my life.
What difference will it make if he knows or not?
I don't think it makes a lot of difference what colour it is (= it is not important) .
'Shall we go on Friday or Saturday?' 'It makes no difference (to me).'