Some different recipes for grilling corn on the cob involve grilling it in the husk, inside aluminum foil or without the husk on the grill. The primary difference between using the husk or foil and leaving the corn unwrapped has to do with the texture of the corn.
When grilling corn in the husk, take off the outer layer of the husk and remove the silk before folding the husk back into place. This gives the heat more access to the corn itself. Soaking the corn in cold water softens the kernels for the grilling process. Grill for 15 to 20 minutes, turning the corn every 4 or 5 minutes, until the kernels are tender.
Grilling in foil is similar to the husk method, except that the cook takes off the husk with the silk, wrapping the corn in foil instead. Serving corn grilled in foil is easier, as unwrapping is less complicated than taking the husks off after some time on the grill.
Grilling the corn unwrapped puts the sear marks right on the corn itself, leaving some pieces crispy and black. This also requires minimal seasoning, as the time on the grill gives the corn a smoky flavor. It does not turn out as juicy this way, but the drier texture has more of the flavor of the grill.