When professors talk about scholarly information, they may refer to it in many ways:
All of these essentially mean the same thing. And it hinges on peer review.
What is peer-review? Researchers produce scholarly information that usually goes through a peer-review process. This means that other scholars (peers) have reviewed the information (usually in the form of a scholarly article) and decided that it is of good quality and meets the standards established for the discipline.
Peer review and publication takes a lot of time. There can be a year or more between submission and publication. The process is also highly competitive. For example, some journals only accept about 10% of all the articles they receive.