As an avid reader, I’m sure you know the difference already:
Traditional Publishing is where an author gets a contract with one of the big publishing houses, via an agent, and the publisher handles a lot of the editing, cover design, marketing etc. Prices for physical books can be lower because the publisher orders hundreds/thousands of copies up front.
Indie (or self) Publishing is where, as well as writing the book(s), you do all of the extra work too, and publish the work yourself via platforms like Amazon and others, to get your book out into the world.
Put like that it sounds like a no-brainer, but it’s not so simple. Traditional publishers want safe bets – hence all the celebrity books from people they know will sell. It’s incredibly hard for an unknown author to get a deal – why would they take a chance on someone new? They also expect an author to do a lot of publicity and marketing, so it’s not the easy ride people think it is – unless maybe you’re James Patterson or Lee Child, but I bet they do a lot more than just sit writing books too.
Of course, I’m biased, as an Indie author, but it does give you control over what you produce. Traditional publishers employ ‘sensitivity readers’ to police what should and shouldn’t be included, so an author’s words can be heavily edited to avoid offending people. Maybe you think that’s a good thing, but it’s something else to bear in mind.
Yes, self-publishing does mean that there are some lower quality books out there, but there are plenty of traditionally-published stinkers around, and the good books will always rise to the top, however they arrive on the market. And you’ll discover lots of new authors and genres without having them filtered out by agents and big businesses. And more books = good right?
And then there’s Vegas (see separate post)