There's traditional publishing, self-publishing and everything else (POD, etc.)
Traditional publishing is where you submit your manuscript and hope someone takes interest and they sign you to a publishing deal. There are exceptions to the rule, but for the most part the publisher owns the copyright in exchange for and advancement against future royalties you may or may not earn. You receive a very small percentage from the sell/sale of every book once you have recouped the advancement that was given to you when you initially signed your publishing deal. By small I mean 5% to 10%, may be a little lower and maybe a little higher.
With true self-publishing you do everything the traditional publisher will do accept you retain ownership of your copyrights and keep anywhere between 40% to 97% of the profits when your books are sold. Additionally, you don't get and advancement, rather you invest money into editing, production and marketing, etc.
POD, etc. is when a company provides some or all of the services of publishing your book. Sometimes you retain your copyrights and sometimes you don't. (READ THE FINE PRINT)
Having written and self-published How to Self-Publish for Profit, the Music Industry Connection Book Series, the Modeling Industry: Secrets Revealed and having known several authors that have been published through traditional publishing houses I encourage most writers to self-publish their own books. Given you sell a large number of books in your state or region you may become the recipient of more favorable traditional book publishing offers.
You're invited to join the WORLD WIDE PUBLISHERS PUBLISHING Community for writers, authors and book publishers. The community is set up for high level communication (networking) and to turn that networking into business (money) for writers, authors, book publishers and anyone associated with the publishing business. Visit the links in this message for details.
"THINK, PLAN, EXECUTE!" -JaWar