What is Copyright Infringement?

Legal Definition
Copyright infringement is the use of works protected by copyright law without permission, infringing certain exclusive rights granted to the copyright holder, such as the right to reproduce, distribute, display or perform the protected work, or to make derivative works. The copyright holder is typically the work's creator, or a publisher or other business to whom copyright has been assigned. Copyright holders routinely invoke legal and technological measures to prevent and penalize copyright infringement.

Copyright infringement disputes are usually resolved through direct negotiation, a notice and take down process, or litigation in civil court. Egregious or large-scale commercial infringement, especially when it involves counterfeiting, is sometimes prosecuted via the criminal justice system. Shifting public expectations, advances in digital technology, and the increasing reach of the Internet have led to such widespread, anonymous infringement that copyright-dependent industries now focus less on pursuing individuals who seek and share copyright-protected content online, and more on expanding copyright law to recognize and penalize – as "indirect" infringers – the service providers and software distributors which are said to facilitate and encourage individual acts of infringement by others.

Estimates of the actual economic impact of copyright infringement vary widely and depend on many factors. Nevertheless, copyright holders, industry representatives, and legislators have long characterized copyright infringement as piracy or theft – language which some U.S. courts now regard as pejorative or otherwise contentious.
-- Wikipedia