By default, the creator of a work (its author) owns the copyright in the work. A major exception to this is that an employer generally owns copyright in works created by its employees, though UNT and most other universities allow employees to keep the copyright in certain scholarly and creative work: see Who Owns the Copyright: UNT or Me?.
A scholarly publisher will therefore need to get the author’s permission in order to publish their work. Some publication agreements require you to assign your entire copyright over to the publisher in exchange for publishing your work. This means that, upon signing such an agreement, you will lose all control over your work in exchange for publication. Your work would then belong to the publisher, though some publishers grant certain rights back to the author as a courtesy, such as the right to distribute the author's journal article in the classroom or to republish it as a book chapter.
However, publishers do not actually need to own a copyright to publish an article. Instead, they only need certain rights to distribute the work. As the author, you can to negotiate to keep your copyright and instead give the publisher a non-exclusive license to distribute the work.
In deciding whether or not you are willing to transfer your entire copyright to a publisher, consider what you want to do with your work besides have it published. Retaining ownership of the copyright ensures that you will be able to do all of the following without constraints:
Include it in future works like your dissertation or thesis
Produce a revision with corrections or updates
Make it available to your students
Allow colleagues to reuse parts of your work in their writing
Be sure to carefully read a publication agreement involving transfer of copyright to see if you retain rights like these after signing the agreement. If these rights are not included in the agreement, and you would still like to retain them, try to negotiate with the publisher. See Understanding and Negotiating Book Publication Contracts(from the Authors Alliance) and the SPARC Author Addendum.