There really magnets, which allow currents to flow into the amp from the guitar. The greater the vibration the greater the sound. There the shiney parts of guitar if there covered. Fenders have 3 of them traditional, les pauls and arch tops have 2 of them and they all sound different from each brand and type so be selective. Fenders are single coils and have a higher, less beefy scream to them, while humbuckers (les paul type pickups) provide a "fatter" beefy tone that sounds thicker then the fender. One isnt better then the other, just preference. Name some artist and i will tell you if they use single coils or humbuckers. Dont rule out Fenders dude cuz thier mexican strats are compedititve to the les pauls. The pick ups should be upgraded on them two. There are a bazillion pick ups out there so try before you buy, if not pick a artist who sounds you like and choose like that, if there not distorting thier sound to much. Or go to websites and listen to thier demos, but thier misleading as they are pumped through good guitars and recording machines that make them sound pretty good.