The first sale exception (§109) copyright allows an owner of a work to lend, rent, or otherwise dispose of the work. Because of this, libraries can lend, people can sell videos or books at their garage sale, Amazon call sell new and used books, and second hand book stores are a legitimate business.
Libraries can also lend their materials for educational use and educational screening in classroom settings.
If the library has a DVD you would like to show in your class or place on reserve for your students to have access to, please contact us! Additional information on placing materials on course reserve can be found here.