thumb|Counterfeit products at a flea market. A counterfeit product is an imitation which infringes upon a production monopoly held by either a state or corporation. Goods are produced with the intent to bypass this monopoly and thus take advantage of the established worth of the previous product. The word counterfeit frequently describes both the forgeries of currency and documents, as well as the imitations of clothing, software, pharmaceuticals, watches, electronics, and company logos and brands. In the case of goods it results in patent infringement or trademark infringement.

Counterfeiting of money is usually pursued aggressively by all governments. The ethics of counterfeiting goods on the other hand is looked at differently in different areas of the world.

Counterfeiting of money

Counterfeit money is currency that is produced without the legal sanction of the state or government.

Counterfeiting of documents

main: Forgery

Forgery is the process of making or adapting documents with the intention to deceive. It is a form of fraud, and is often a key technique in the execution of identity theft. Uttering and publishing is a term in United States law for the forgery of non-official documents, such as a trucking company's time and weight logs.

Questioned document examination is a scientific process for investigating many aspects of various documents, and is often used to examine the provenance and verity of a suspected forgery. Security printing is a printing industry specialty, focused on creating documents which are difficult or impossible to forge.

Counterfeiting of consumer goods

Some see the rise in counterfeiting of goods as an inevitable product of globalization. As more and more companies, in an effort to increase profits, move manufacturing to the cheaper labor markets of the third world, areas with weaker labor laws or environmental regulations, they give the means of production to foreign workers. These new managers of production have little or no loyalty to the original corporation. They see that profits are being made by the global brand for doing little (other than advertising) and see the possibilities of removing the middle men (i.e. the parent corporation) and marketing directly to the consumer.

Certain consumer goods, especially very expensive or desirable brands, or those which are easy to reproduce cheaply, have become frequent targets of counterfeiting. The counterfeiters attempt to deceive the consumer into thinking they are purchasing a legitimate item, or convince the consumer that they could deceive others with the imitation. An item which doesn't attempt to deceive, such as a copy of a DVD with missing or different cover art, is often called a "bootleg" or a "pirated copy" instead.