Copyright is automatic and protects both published and unpublished original works.
You know what you write, but do you know your rights?
Often when an author publishes they sign a copyright transfer agreement or a publishing agreement. In a copyright transfer agreement you typically will sign over the full copyright to the publisher.
The agreement may allow you to retain such rights, but you no longer hold copyright. You likely won't be able to do the following:
It is very possible that you would be violating copyright on your own article. Be sure to read your agreement to know your rights and negotiate the agreement.
Know your rights before you sign a publishing agreement!
This video overviews a copyright transfer agreement to familiarize you with how to understand a copyright transfer agreement, what to look out for in your journal publishing contracts, and your options.
Publishers only need a license to publish, not your full copyright. By negotiating your publishing agreements you can retain more of your rights as an author.
Below are links to the general copyright and archiving policies for major publishers. If your publisher is not included in this list you can look them up in the SHERPA/RoMEO database, or consult the publisher's website.