What is dating?

I remember a strange conversation I had with my boyfriend, where I said we were dating but he said that we were doing something more meaningful, screening to see whether we would make for good spouses to which I responded “Yes, we are dating”.
I looked up online and maybe there is a term more appropriatethan dating, serious dating, though it still leaves me quite confused as it implies there’s casual dating which is different than going out with someone for dates. This sub is even more confusing because it’s called dating but it’s not for people in long term relationship, which makes me wonder whether dating just refers to the non exclusive stage, that boyfriends and girlfriends aren’t dating but are…..? Also the couples that live together don’t seem to refer to their relatioship as dating, or serious dating, anymore.
Here are the terms on which I’d like some clarification

– does going on dates with someone non exclusively count as dating that person? Or it only counts as if it’s exclusive?
– does going on dates with someone non exclusively count as casual dating whereas it becomes serious dating if it’s exclusive?
– does any kind of romantic interaction not geared towards marriage count as casual dating whereas serious dating takes marriage into account?
– is serious dating the same as courtship or does courtship start after there has been an engagement?
– when does dating start and at which point of the relationship does it not count as dating anymore? And when does casual dating end and seious dating start?

Thanks