Copyright: When a person creates something on the internet the legal rights to it are owned by that person. Another person may not use their same ideas without given consent.
Plagiarism: When a person takes another person's ideas and claims them as their own. It is a crime that can be punishable by paying fines anywhere from $200-$150,000
Fair Use: When, under certain circumstances, a person is allowed to use verbatim copyrighted material. Such circumstances could include: teaching, critiquing, and news reporting.