Assuming that the confusion is a difference in Scottish and North American Halloween tradition, Jack o' Lanterns are objects, typically pumpkins, with carvings of faces or pictures in the side. The interior is then illuminated, so that the face or image glows at night.

Also, Google is showing me that a "Jack's Lantern" is a pumpkin ale, but I'm pretty sure you'd need more than just a tin can to make that.

Hope that helps.