A textbook exchange is the selling or trading of

textbook A textbook is a book containing a comprehensive compilation of content in a branch of study with the intention of explaining it. Textbooks are produced to meet the needs of educators, usually at educational institutions. Schoolbooks are textbook ...

s used from a previous college semester to students needing that textbook for the current semester. It is primarily aimed to fight the rising cost of college books.New York Times: Sometimes, It's Not the Tuition. It's the Textbooks
/ref> Exchanges may be made at the college bookstore or through a website.

References

Bookselling {{retail-stub