The document discusses using QR codes in the classroom. It begins by explaining what QR codes are and how they were invented. It then provides examples of how QR codes can be used for scavenger hunts, review games, and linking to supplemental materials. The document also discusses QR code generators that teachers can use to create their own codes linked to web content for classroom assignments and activities. It emphasizes that QR codes provide an engaging way for students to access multimedia resources through their mobile devices.