To publish a book is all about what you are looking for as a writer.
Some people want only to publish through a publisher. Others, want to publish on their own, I am one of them.
I enjoy having total control over all decisions that concern the book. Writers that publish through a publisher has no say in what the cover will look like, or how many copies will be printed. But that is also a reason that people want to publish through a publisher. To not have to do it all themselves. We are all different.
Doing it all yourself is much more work, you have to make sure the book is proofread, evaluated by an editor, gone through, again and again for mistakes. It is your job to make sure the book is at a level that can compete with the best of the best out there.
You also have to get an ISBN (a code) and then format your book before publishing.
Writing the blurb is another thing a writer that does it all themselves has to do, the blurb is the text that is the most difficult to write. You have to sum up the book for the buyer and that is not easy.
I have worked on my blurb for about 5 years, that says something about how difficult it is to write.
If you publish through a publisher, depending on if you are a new and unknown writer, you have to be prepared to do a lot of marketing yourself.
That is something I know I have to do since I am doing it all myself.
If you publish yourself, there are a lot of options out there, depending on what you are looking for. There are platforms like Amazon, where you can do it all yourself.