Shower heads are fixed in position by a shower arm (Sold separately but generally they have generic fittings) that comes out of the wall or ceiling. They are normally set quite high so that the person showering can stand underneath them and shower as if standing under a waterfall. Please check that you have good enough water pressure to operate the shower head you choose, otherwise you will be standing under a bit of a dribble of water. You will probably need a minimum of 1 bar water pressure for the most basic shower head.