It can go both ways. E.g. often, experimental physicists will try to prove/disprove a priori predictions from theoretical physicists. Theory is just an explan

It can go both ways. E.g. often, experimental physicists will try to prove/disprove a priori predictions from theoretical physicists. Theory is just an explanation of hw the world works: you can come up with that explanation as a reason for observations, or as a logical consequence of other theories (which is then verified by observation).