Under both types you have free access and permission to:
OER can include textbooks, videos, simulations, assessments, lecture notes and even full courses!
It is unlikely that you will find one OER that perfectly fits your needs and you'll need to do some digging, but we think you'll be pleasantly surprised by the breadth, variety and quality of materials available. There is no one definitive source for finding them, but the links below provide a wide range of search engines and sources. If you find something we've missed, please let us know and we'll add it to the list. We love OER!