A CAST COUNTERFEIT is a replication of a genuine coin usually created by making molds of the obverse and reverse, then casting base metal in the molds. A seam is usually visible on the edge unless it has been ground away.
A STRUCK COUNTERFEIT is a fake coin produced from false dies.
A CONTEMPORARY COUNTERFEIT is a coin, usually base metal, struck from crudely engraved dies and made to pass for face value at the time of its creation. Sometimes collected along with the genuine coins, especially in the case of American Colonial issues.