Preprints are complete pieces of scientific work shared online before the completion of journal-organized peer review. Preprints are often the same manuscripts that are submitted to a journal for peer review, but are stored on freely accessible public servers such that they become available to the whole web community within 1-2 days from submission. Usually preprints are posted on preprint repositories either before or at the same time as submission to a journal. Most journals will accept manuscripts that have previously been submitted to a preprint repository (check out SHERPA/ROMEO, a tool that will help you learn about publishers’ copyright policies and self-archiving).