"Self pub" is short for self-publishing, which means to independently create, produce, and distribute your own book or other written work without the involvement of a traditional publishing company. Full definition
IMO, the conversation on self pub revolves too often around the platforms and methodologies of publishing, and not enough around the sharing of game changing ideas. (thecreativepenn.com)
I have been a literary agent in traditional publishing for 20 years but now am moving into self pub. (wiseinkblog.com)