The phrase "instructional materials" refers to things like textbooks, worksheets, videos, or any other resources or tools used to help teach and learn new things. Full definition
Computer training and development of instructional materials for new and existing employees. (livecareer.com)
The district will also freeze the purchase of textbooks and other instructional materials for the remainder of this school year to save $ 30,000. (articles.chicagotribune.com)
This resource gives districts and schools some breathing room until fully aligned instructional materials are available. (ascd.org)