In addition to section 108, section 107 is important to libraries because it contains an exception to the exclusive rights of owners to make and distribute copies of their works. It states that "the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright." To determine whether the use of a work is a fair use, the following four factors are to be considered: purpose and character of the use, nature of the copyrighted work, the amount and substantiality of the portion used in relation to the whole, and the effect of the use on the potential market. See Title 17of the U.S. Code.