Fair use is a part of Copyright Law that allows certain uses of copyrighted materials without needing the creator's permission. It is essentially rulebook for when it's okay to use copyrighted materials.
In Copyright Law, a special section exists concerning fair use for libraries and archives: Section 108: Limitations on Exclusive Rights - Reproduction by Libraries and Archives.
The best thing about fair use is that it lets libraries share the stuff they've paid for with their members without asking the creator again. So, if you are a student of the University, you can use the content in your courses and share it with your classmates through links.
But remember, fair use doesn't mean you can use anything however you want, and it doesn't say copyright rules are too strict. It's a careful balance that looks out for both creators and users. It's all about making sure creators get fair credit and payment while still letting folks access content fairly.
Adapted from: https://fairuse.stanford.edu/overview/fair-use/four-factors/
From: https://musc.libguides.com/copyright/fairuse#loaded