Copyright Overview: Copyright Coverage
Copyright protects original works of authorship that are fixed in a tangible form of expression. That can mean "put on paper or canvas", but it also includes things that require a machine - such as a camera or a computer - to view.
Copyrightable works include:
These are the kind of things we generally think of as copyrightable - but everything we create, from the doodle on the margin of our notes to the presentation we prepare for a class - is covered by copyright, once we fix it in a tangible form.
An idea is not copyrightable. The idea fixed into tangible form is copyrightable.
To do your own detective work on this, see the US Copyright Office's Circular 1: Copyright Basics.
Source: The information on this web page is based on the Copyright Office and Austin Community College.