Forgery is a crime. It is the process of making, drawing, or altering a document with the intent to defraud. A person is guilty of forgery if s/he alters any writing or makes any writing of another person and proclaims it to be the act of the other person who did not actually authorize the act.
Counterfeiting is criminal imitation. It is done with the intent of fraudulently passing off the counterfeited product as genuine. Generally, counterfeit products are made with the intent to take advantage of the established value of the imitated product. Although the term counterfeit is generally associated with making, dealing, or possessing any counterfeit currency, it also includes forgeries of documents and imitations of goods and trademarks. In the case of goods, counterfeiting results in patent infringement or trademark infringement. Making, dealing, or possessing any plate, stone, analog, or any other thing, or part used for counterfeiting also amounts to the crime.