Traditional book publishing is when a publisher offers the author a contract. In turn, they print, publish, and sell your book through booksellers, wholesalers and other channels. The publisher buys the right to publish your book and pays you royalties from the sales.
To find the right publisher you will need to do some research.
Once these steps are accomplished, you're ready to write a query letter.
Most publishers will ask that submissions to be uploaded to their websites, but each publisher is unique and may have different ways in which they want materials submitted.
*A note about agents
Some writers of trade books work with agents. Most agents only accept clients who have already published a book or have a track record to draw upon. Most publishers would advise new writers to approach them directly, and not try to first find an agent.
The author either has the skill set to publishing his or her own book, or employs professionals to do so. The author largely creates his or her own experience. Independent publishing requires that authors have in-depth industry knowledge, management skills, and a way to finance and bring their own book to market. It can be a high risk choice.
With a company: Authors who publish with the help of a self-publishing company are also self publishing. This is because the author is financing the majority of the publishing process. Some self-publishing companies offer publishing services to authors. Examples of services commonly offered include ISBN assignment, book cover design, interior layout, editing, distribution, and marketing. Some companies only get the book printed, while others mimic traditional publishing houses, providing a full set of publishing and marketing services. Friesen Press provides excellent information to authors who wish to explore this option:
Friesen Press: https://www.friesenpress.com/.
Open Access publishing
Publishing with the library