Copyright is a right that says the creator of their work can use their work freely and how ever they want. Nobody else is allowed to use or sell their work without permission.
Fair Use is a limitation and exception to the exclusive right granted by copyright law to the author of a creative work. This permits limited use of copyrighted material without acquiring permission from the rights holders..
The unauthorized use or reproduction of another's work.
The practice of taking someone else's work or ideas and passing them off as one's own.
On the Internet this is the word used to describe the trail, traces or "Footprints" that people leave online.