You’re welcome, I’m glad that this explanation made sense.

They are like places we’re electrons could be, you could also call them „electron holes“. If an electron flows through a conductor, it kicks of other electrons bound to atoms taking their place, which then become free electrons, it’s like a chain reaction without the amplification thing

You could say electrons flow from left to right but you could also say that holes flow from right to left, most components like resistors don’t care.

But semiconductors like diodes do, they’ll heat up very quickly.

For most household appliances this is completely irrelevant because the sine potential (and the current flow it causes) change directions every (depending on where you live) 10ms. Yes your phone is semiconductor based but your phone charger rectifies that into a DC voltage with defined polarity