Copyright law gives copyright holders control over how their copyrighted works are used. While using copyrighted material without permission is generally forbidden, fair use allows educators to use limited portions of copyrighted works for classroom instruction without obtaining permission. Fair use has limitations on how much and how the copyrighted content is used; commercial use or using an entire work requires obtaining permission from the copyright holder. Users should cite their sources properly and obtain permission if unsure about fair use when using copyrighted content.