Prior to submitting your manuscript to a journal, it is important to take time to consider how you would like your work to be utilized and disseminated. In the future, you may wish to give copies of your work to colleagues, use your work for instruction, post a copy of your work to an online repository, or present the work at a professional conference.
As an author, you have rights over your intellectual property and the ability to transfer or retain full (or partial) rights of the publication. Researching a journal's publishing contract to find the copyright transfer agreement is where you will discover what rights to your work you may retain and consider if negotiation is needed. Unless addressed in the transfer agreement, you may be forbidden by the publisher to share or use your work in the future.