Copyright law covers all “original works of authorship fixed in any tangible medium of expression,” whether published or unpublished.
A work is considered original if it “embodies some minimum amount of creativity.” For example, a how-to manual or a particular arrangement of data may be considered original works.
Fixed means that the work exists in a form that has “more than transitory duration.” A cake decorated with a Happy Birthday message is unlikely to be fixed, but a website almost certainly is.
Tangible medium of expression refers to what can be seen, heard, or felt, either directly or with the assistance of a machine or device now known or later developed.
Such works include, for example:
Copyright protection does not extend to:
Use the information in section 6 of this guide, “When Works Pass into the Public Domain,” to determine the copyright status of the work you wish to use.
 Kenneth D. Crews, Copyright Essentials for Librarians and Educators (Chicago: American Library Association, 2000), 9.