This briefing discusses the history and role of preprints in the biological sciences within the evolving open science landscape. The focus is on the explosive growth of preprints as a publishing model and the associated challenges of maintaining technical infrastructure and establishing sustainable business models. A preprint is a scholarly manuscript posted by the author(s) to a repository or platform to facilitate open and broad sharing of early work without any limitations to access. Currently there are more than 60 preprint servers representing different subject and geographical domains, each one evolving at a different based on adoption patterns and disciplinary ethos. This briefing will offer invaluable help to those who wish to understand this rapidly evolving publishing model.