Protected...and not.
In general...
Protected material is original expression that is fixed in a tangible medium of expression. Only minimal creativity is required.
Yes
Literary
Music and lyrics
Dramatic
Pantomimes & choreography
Pictorial, graphic, sculptural
Motion pictures
Sound recordings
Architectural works
No
Ideas
Procedures & processes
Systems
Methods of operation
Concepts & Principles
Discoveries
Blank forms
Works in the Public Domain