i have new aquarium fish and i was hoping sum1 cud help me

Hi i think my sum of my fish have sufferd with ick and i need to no if any1 can help me by telling me what it is and wot happens to your fish as our fish have some funny looking thing on there scales and the fish infected are just floating around the tank upside down and they just seem to be very limp please if you know what it is could you let me know and wout i should do to get rid of the infection

thank you all
Emma