Copyright infringement occurs when someone uses, copies, distributes, or sells copyrighted material - such as music, movies, software, or written works - without the permission of the copyright owner. This unauthorized use violates intellectual property laws and can lead to legal consequences. Copyright laws are designed to protect the rights of creators and ensure they are compensated for their work. Infringement can happen intentionally or unintentionally, but both can result in penalties, including fines or lawsuits. Common examples include downloading pirated movies, sharing copyrighted images online without consent, or using software without a valid license.