As with anything new in someone’s life - whether it’s a new job, or a new recipe or even a new game, you have to learn about it before you can say you understand it. Same thing goes for poker.
It is a usually known reality that poker has various kinds. The fundamental principle of poker which is you must win the Showdown phase where you show combination of cards to your opponent and prove that your set is relatively better than your opponents, basically still hold true for each variation even if each is different in one way or another. Along the way, you will be given chances to call, raise or fold - chances which are also given to your opponents. One’s card combinations and bluffing skills are the main determiner for winning in all variations. But the different kinds of poker offer basically different poker experiences. It’s best that you know what each is about to choose what kind of game you will play.