QR codes can be created for free online and contain information that links to websites, files, contact details when scanned by smartphones. They have various educational uses including providing additional context on field trips, embedding questions to encourage deeper learning, linking to reference materials, instructional videos, or music. QR codes could also be used for communication purposes like sharing calendar events, emergency contacts, or wifi login credentials. The document provides examples and resources for using QR codes in both classroom and outdoor learning environments.