The Basics

According to opencontent.org, the terms "open content" and "open educational resources" describe any copyrightable work (traditionally excluding software, which is described by other terms like "open source") that is licensed in a manner that provides users with free and perpetual permission to engage in the 5R activities:

1. Retain - the right to make, own, and control copies of the content (e.g., download, duplicate, store, and manage)
2. Reuse - the right to use the content in a wide range of ways (e.g., in a class, in a study group, on a website, in a video)
3. Revise - the right to adapt, adjust, modify, or alter the content itself (e.g., translate the content into another language)
4. Remix - the right to combine the original or revised content with other material to create something new (e.g., incorporate the content into a mashup)
5. Redistribute - the right to share copies of the original content, your revisions, or your remixes with others (e.g., give a copy of the content to a friend)

How do you know if the 5 Rʻs are allowed? See Copyright for OER

Definitions
Here are a few definitions from Open 101: An Action Plan for Affordable Textbooks:

• Traditional textbook
  A printed text, peer-reviewed and faculty-written, that is published under closed copyright. This is the basic product that has dominated course materials lists for decades, and is published by an academic press or one of the large commercial publishers like Pearson.

• Open textbook
  A peer-reviewed and faculty-written text that is published under open copyright and freely accessible online. The open license means that anyone can freely download, edit, and share the content with attribution to the original author. OpenStax, based at Rice University, is a popular publisher of open textbooks.

• Open educational resource (OER)
  As defined by the Hewlett Foundation, OER are “teaching, learning, and research resources that reside in the public domain or have been released under an intellectual property license that permits their free use and re-purposing by others. Open educational resources include full courses, course materials, modules, textbooks, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge.”

• E-textbook
  A digital version of a textbook. Typically, these are hosted on a secondary platform like VitalSource or RedShelf. While often available at a lower price point, these digital rentals come with limitations that students don’t like- such as copy-paste or print limitations. Additionally, many e-texts that are sold to students at the campus bookstore expire just like access codes do.

• Access code
  A string of letters or a login that grants a user term-limited access to various supplemental resources like homework, quizzes, and exams. Access codes can only be redeemed once, and often students cannot retain the coursework hosted online at the end of their course.

• Bundling
  The act of combining a textbook (e-text or traditional) with an access code and/or other supplemental materials like a lab manual. The pervasiveness of bundled textbooks with access codes means that students cannot resell the book- or will receive pennies on the dollar for the resale.

• Custom edition
  A version of a textbook created by the publisher specifically for a school or professor, adding or rearranging content to suit their needs. These can only be bought and sold on-campus, reducing opportunities to cut costs by buying used online. In some cases, these are sold without a binding in loose-leaf (or “a la carte”) format that is impossible to resell. Custom editions can sometimes be conflated with bundles, since a book labelled “custom” may simply bundle with a “generic” textbook with a supplemental access code, rather than an actual  custom edition of a book.

• New edition
  An updated version of a textbook, typically every 2-4 years. Publishers claim this is to update facts, graphics, and other features, but our previous research found that these changes are merely nominal. The frequent revision of textbooks is a classic publisher  tactic to undermine the used book market, since when faculty adopt a new edition, students cannot resell older editions at the end of the class. Sometimes, professors will assign an older edition of a textbook to help students find cheaper used versions, but after a few years the online used book market dries up and students must purchase higher-priced books from the campus bookstore.