An open textbook is like a commercial textbook, except: (1) it is publicly available online free of charge (and at low-cost in print), and (2) it has an open license that allows others to reuse it, download and revise it, and redistribute it. This book has a Creative Commons Attribution license, which allows reuse, revision, and redistribution so long as the original creator is attributed (please see the licensing information for this book for more information).

In addition to saving students money, an open textbook can be revised so that it is designed to support a particular course. In a recent study of undergraduate students in an introductory level physics course, students reported that the thing they most appreciated about the open textbook used in that course was that it was customized to fit the course, followed very closely by the fact that it was free of cost (Hendricks, Reinsberg, and Rieger 2017). For example, in an open textbook one may add examples relevant to your particular version of the course, or embed slides, videos, or other resources.

A number of commercial publishers offer relatively inexpensive digital textbooks, but these may have certain limitations and other issues:

• Access for students is often limited to a short period of time;
• Students cannot buy used copies from others, nor sell their own copies to others, to save money;
• Depending on the platform, there may be limits to how students can interact with and take notes on the books, for example students may not be able to export their notes outside the book, so lose access to those as well when they lose access to the book.

None of these limitations apply to open textbooks like this LGBTQ+ Studies: an Open Textbook. Students may download any chapter in this book and keep it for as long as they wish. They can interact with it in multiple formats: on the web, offline as a PDF, or as a physical print book purchased at cost.

See the next section, “How to Access and Use the Books,” for more information on what the open license on this book allows, and how to properly attribute the work when reusing, redistributing, or adapting.