Publishers don't often use the word feedback. They are more likely to call it 'editorial input' or 'comments'. Or, of course, 'rejection'. But feedback is what the rest of the world calls it when someone tells you what they think of your work and how you should change it to improve it (or not bother).
Feedback in a creative writing course aims to help the student to become a better writer and to improve the specific piece of writing they have submitted. In an ideal world, feedback from a publisher would have the same aims, but generally the publisher is only interested in improving the current piece of writing - the one they are paying you for (or might pay you for if you can make it good enough). There is also feedback from agents. If you already have an agent, their feedback will be aimed at making you a better writer, and also at improving the current piece of writing.
'Improving' is a tricky term. It doesn't necessarily, in the vocabulary of agent and publisher, mean making the work aesthetically better, though it might include that. Primarily, it means making the work more saleable - because that's the agent's/publisher's job: to sell your work. If I write a totally brilliant piece of young adult fiction that's 20,000 words long, my agent is likely to tell me it's unsaleable. There is no established market for fiction of that length for teen readers. (Of course, I haven't done such a thing - I know there's no market for that. So please don't tell me to self-publish it, because it doesn't exist. Also please don't tell me there is no reason why there should not be such a thing, or list the few exceptions you can find. In general terms, it's not a thing - my agent won't want to try to sell it.)
So what IS in feedback?
In electronics and broadcasting, it's the garbage or white noise that is reflected back, it's interference. Sadly, interference and garbage is just how some writers feel about editorial feedback. They are generally the ones who feel they know best, even if they have never had anything published, and they are often the first to turn to self-publishing. But what feedback should be is intelligent and constructive criticism and commentary.
If you are working with a publisher, you need to remember that they have an idea of the type of book they want to publish and the audience for that book. Their idea will be more or less rigid depending on the type of book.
If it's fiction, they will know the age group they want to target and the approximiate type of reader. Irritatingly, that might be gender-specific. 'A funny novel that will appeal to 8-year-old boys', for instance. 'A romantic teen story with girl-appeal.' Well, you can decide not to work with them if that riles you too much. You can challenge the wording, and they might change it, but they will still be looking for the same thing.
If it's non-fiction it might be more specific still. You might have to address an area of the UK curriculum and also cover various US curricula. Or, if it's a trade book, there could be requirements such as 'a book about technologies developed in the last fifty years; the book will sell into the UK, Australasian and Chinese markets.' That means there must be plenty of Australasian and Chinese examples as well as the UK and US ones you first thought of.
Feedback will point out if you've missed the mark. The thing is, you might have written a perfectly good book, but if it's not the book the publisher intends to publish it isn't any use. Indeed, sometimes you might write a better book than the one that is wanted, and you will have to go backwards to meet the target. This sounds ridiculous, but it's not. Say you have written a wonderful book about technological innovations, but none of them is Chinese or Australasian. You might have to pick some lesser innovations in order for the book to achieve its target of selling into those markets. Or perhaps you wrote a really good story that will appeal to 8-year-old boys, but it's not funny. If the book is to be part of a list of funny books, that's no good, however wonderful your story is.
So the upshot of all this is, that while feedback from a writing group or tutor might be about improving your work in purely aesthetic terms, feedback from a publisher or agent is generally commercially-oriented. A lot of the time, if you are sending your work on spec, you won't get any feedback beyond 'very nice, but not for us right now.' Even that is useful feedback - it makes you think 'what does this editor/agent need right now, and why/how did I get it wrong?' It doesn't (necessarily) mean 'your book sucks; never write to me again.' Of course, if they do say that, that's useful feedback, too. But a bit harder to take.
By the way - one of my daughters, when very young, was asked by one of my publishers to assess a new series he was planning. She read the work, and emailed him without my knowledge. It went: "Dear [publisher] - your series is boring and lacks interest." It was canned the next day. Feedback is useful. (She was right, but I could have wished she had been more diplomatic.)