Nowadays, there are really only two classes:

• The Owners class, which is people who live off the money that's made by the assets they own.
• The Worker class, which is people who live off the money they get from selling their work.

What was called "Middle Class" generally are just workers who earn a bit more, though the older Middle Class did at times manage to save enough to buy enough assets that they could start living of the income from those assets and not have to work anymore. That's not the case for young people nowadays who would qualify as Middle Class due to their level of formal education and the kind of work they do because it's way harder for them to save and asset prices are through the roof.