Working class simply means someone who works for a living. They’re not earning passive income from capital.
An engineer earning $250k a year is working class.
They’ll work for the majority of their healthy lifespan and likely retire with a net worth in the millions unless they’re squandering everything.
If you don’t fall into the category where you actually work then you’re the unemployed poor, not working class.
If you work for fuck all income (below the poverty line despite working) you’re the working poor.
They’re fact you need this explained should really highlight how little you know and understand about economics, employment and wealth.