Often the Submitted Version or Accepted Version of a publication is permitted to be open and uploaded into an institutional repository (e.g. ResearchDirect).
Typically, authors usually assign their copyright to publishers when they negotiate contracts, however, as a researcher, it is important to understand the rights/permissions you have as an author
The Submitted version is the pre-print of the manuscript, paper before peer review. This is the author's version of the article that was sent to a journal for consideration.
The Accepted version is the post-print of the manuscript, paper after peer-review. This is the author's version of an article that has been amended to reflect any revisions in the publication process.
The Published version: the final version as it appears in the publication.
Note: SHERPA/RoMEO database provides a guide to publisher’s copyright policies