(of a writer) publish (a piece of one's work) independently and at one's own expense.
the publication of any book or other media by its author without the involvement of an established publisher. A self-published physical book is said to have been privately printed. The author is in control of the entire process including, for a book, the design of the cover and interior, formats, price, distribution, marketing, and public relations. The authors can do it all themselves or may outsource some or all the work to companies which offer these services.
Self-published books are made to order. If you want to have the physical copy, the author requires you to send the payment first, wait for a month or two before getting your copy. All self-published books are MADE TO ORDER. The author may opt to have few stocked copies but sometimes they only order books that are paid.
Some authors, opt to have printed copies before selling their books but not everyone is lucky as the others. Their books may be bought by the readers but not every single copy will be sold. Loss of income would happen because the money that they used for the printing of their selfpub books wasn't able to return since some copies are stacked around the corner of their rooms.
Selfpublished books may or may not be available in bookstores. It is rare to see selfpublished books in public bookstores since they should also pay the bookstore for having their book on their shelves. So authors opt to sell it online and have it for pre-order.
I asked my friends why self-publish their works even if it's stressing to do the layout and proof read the whole thing. It's not just about the money (they say), they wanted to retain the story itself.
When one work is bought by a book publisher, they opt to have it edited and cut some scenes in the book before they sell it nationwide. What they don't want to happen was that, their story to be cut so they opt to have it self-published.
In self-publishing, they can control what to be included in the book. They can cut scenes which they find not really necessary and add additional chapters before having it self-published.
In self-publishing, the author controls everything: covers, layout, content, designs, etc. They have every right for their work.