An open textbook is an openly-licensed textbook offered online by its author(s). The open license sets open textbooks apart from traditional textbooks by allowing users to read online, download, or print the book at no additional cost.
For a textbook to be considered open, it must be licensed in a way that grants a baseline set of rights to users that are less restrictive than its standard copyright. A license or list of permissions must be clearly stated by the author.
Generally, the minimum baseline rights allow users at least the following:
Many authors also grant rights such as:
Excerpt from Open Access Textbooks.