What is protected by copyright?

Copyright protects the original expression of an idea in a fixed medium. The emphasis is on expression. The work must exist in some physical tangible form. But this can be just about anything, the RAM on your computer, e-mail, software code, magnetic or digital video or audio recording, your lecture notes and PowerPoint slides even a note scribbled on a napkin. It only requires a modicum of originality and a minimal level of creativity.