From “Microform” on Wikipedia:
A scaled-down reproduction of a document, typically either photographic film or paper, made for the purposes of transmission, storage, reading, and printing. Microform images are commonly reduced to about 4% or 1⁄25 of the original document size.
From DePaul University Libraries:
Microfilm preserves fragile documents such as rare books, newspapers and other periodicals by using micro-photography to reduce an image onto a roll of plastic film. Microfiche serves the same purpose but the format is a 4x6" plastic card. (You might see these two formats referred to collectively as "microform".)
All Emory students and faculty can request microfilm reels, but you must request each item.
Some microfilm reels are stored offsite and may take up to 48 hours to arrive at the service desk. Once available, you can check out microfilm on a 3-hour loan. You will receive an email when your microfilm reel is ready and available to be checked out.