There's a lot of confusion out there about indie publishers and self-publishers. Let just get straight to the point. Here is this:
From Judith Briles on AuthorU.org (June 2014)
Don’t Confuse Independent Publishing with Self-Publishing
Indie, Independent and Small Press Publishing Are So, Soooooo Different from Self-Publishing, Vanity Presses and Pay-to-Publish “Publishing”
I’ve said it once, I’ve said it a zillion times: yes, dear author-to-be (and those already published), there is a difference between self-publishing, vanity presses, pay-to-publish, a small press, and independent publishing. Don’t mix them up. Don’t get confused.
She quotes Wikipedia:
The majority of small presses are independent or indie publishers, this means that they are separate from the handful of major publishing house conglomerates, such as Random House or Hachette. The term ‘indie publisher’ should not be confused with ‘self-publisher’, which is where the author publishes only their own books.
Defined this way, these presses make up approximately half of the market share of the book publishing industry.
This is a great article if you're confused about any of these terms. Go and check it out.
Unfortunately, I feel the term independent publishing (Indie) is going the same way so many words have already gone--Verbicide. It is used so frequently in the wrong sense that it's original meaning is becoming lost.