The copyright infringement of software (also known as software piracy) refers to several practices when done without the permission of the copyright holder:

• Creating a copy and/or selling it. This is the act that some people refer to as "software piracy". This is copyright infringement in most countries and is unlikely to be fair use or fair dealing if the work remains commercially available. In some countries the laws may allow the selling of a version modified for use by blind people, students (for educational product) or similar. Differences in legislation may also make the copyright void in some jurisdictions, but not the others.
• Creating a copy and giving it to someone else. This constitutes copyright infringement in most jurisdictions. It is not infringing under specific circumstances such as fair use and fair dealing.
• Creating a copy to serve as a backup. This is seen as a fundamental right of the software-buyer in some countries, e.g., Germany, Spain, Brazil and Philippines. It can be infringement, depending on the laws and the case law interpretations of those laws, currently undergoing changes in many countries. In the US, legal action was taken against companies which made backup copies while repairing computers (see MAI Systems Corp. v. Peak Computer, Inc. (1993)) and as a result, US law was changed so that making temporary backup copies of software while repairing computers is not copyright infringement.
• Renting the original software. Software licenses often never restrict the usual right of a purchaser of a copyrighted work to let others borrow the work. In some jurisdictions the validity of such restrictions are disputed, but some require permission from the copyright holder to allow renting the software.
• Buying the original software. Licenses never say that the buyer does not buy the software but instead pays for the right to use the software. In the US, the first-sale doctrine, Softman v. Adobe and Novell, Inc. v. CPU Distrib., Inc. ruled that software sales are purchases, not licenses, and resale, including unbundling, is lawful regardless of a contractual prohibition. The reasoning in Softman v. Adobe suggests that resale of student licensed versions, provided they are accurately described as such, is also not infringing.
• Bulletin Board Sharing/Internet Piracy- Albacea et al (2005) states that this infringement occurs when System Operators share (by electronic transfer) copyrighted materials on bulletin boards or the internet for users to download.

Copyright infringement of software is extremely common in the United States, Mexico, China, Indonesia, Russia, Brazil, Zimbabwe and several other parts of the world. Most countries have copyright laws which apply to software, but they are better enforced in some countries than others. Since a dispute over WTO membership between Iran and USA, which led to the legalization in Iran of the distribution of software without the permission of any copyright holder (see Iran and copyright issues), there have been fears that world governments might try to use copyright laws and enforcement politically.

The rate of copyright infringement of software in the Asia-Pacific region has been estimated at 53% for 2004, and over 90% in regions such as Vietnam. China is the largest producer of pirated products in the world - software is no exception. The Business Software Alliance estimates that in 2006 82% of the PC software used in China was pirated. After joining the World Trade Organization (WTO) China has adjusted its Intellectual Property (IP) laws to comply with the WTO Agreement on Trade - Related Aspects of Intellectual Property Rights (TRIPS). The laws are in place but are ignored.