https://lemmy.blahaj.zone/comment/6039327

" if you’re under retirement age and quit your job tomorrow, do you have enough assets to comfortably live out the rest of your life"

This gets to it. Basically bourgeoisie is the owning class and proletariat is the class that can only survive via labor, but as the post says it's a bit more complicated these days. You could have a business owner or landlord who gets the same amount of paycheck as say a high-paid tech person, or actor, or doctor, or something. And the former is petty bourgeois and the latter is not, because the former owns assets and the latter, if they lose their job, will before long need to find another one in order to survive.

Now you could have someone getting a wage that's been high enough for a long enough time that they have been able to acquire assets that could bring in income, which changes things somewhat. But the main thing to analyze is the relationship to resources, land, and means of production.