The difference between complaining and whingeing is huge. Both are useful at times, and can be done well or poorly. I'm guilty of both, but one is more healthy than the other, apparently. And they go well beyond the boundaries of overcooked food in a cafe.
Whingeing is when you belly-ache to people who can't do anything about the problem.
A habitual whinger is a miserable sod who makes everyone around them miserable too. They are so focused on belly-aching about their lot, they can never even think about what might bring about a possible solution.
In fact, they don't necessarily want a solution. Some whinge to find attention, or gather a group of others around them who agree with them and boost their sense of power, or they may hope to manipulate someone else to speak on their behalf, or they may like to deflect personal responsibility, or drag others down so they don't look so bad themselves.
I reckon whingeing can be useful, if it's done privately with someone you trust, and it's a short emotional-dump of emotion that doesn't go on and on and temporarily allows the whinger to offload. It's not a problem-fix, just a temporary 'steam release'.
The dangers with whingeing is that it can become habitual and generally unhelpful. In fact, I have never met a whinger who is a happy whinger. They damage relationships, careers, emotional and social health - and not only of the whinger. Like I said, miserable sods.
Complaining is speaking to somebody who can do something about the problem. It's solution focused and is often accompanied by the desire to find a mutual resolution.
It's harder than whingeing, because to face up to the right person means you are taking a risk.
In my view, a properly done complaint can be a very powerful transaction leaving everyone more respectful and mutually intent on a solution.
So what comes out of your mouth when you feel irritated or mad? Do you whinge or complain?