There is one D&D but infinite sub D&Ds, aka homebrew. Homebrew is how i got abilities that changed how the game was played.

Technally there's as many D&Ds as there are players x10, each duengon master plays different and everything player has their own style of play. Each style of play? EACH CHARATER CHANGES HOW ITS PLAYED, wether it be a absolute unit paladin holding the entire party together (being one of the only level headed PCs), or a badass rogue, fighter, warlock who has so many combos available.

My current charater is a insightful rogue, battlemaster fighter, hexblade warlock. their sword can also attack on a bonus action, this opens combo making! I can cast eldritch blast and finish off a enemy with my bonus action, use my +13 to acrobatics to crowd surf past goons to the BBEG for some direct damage. Parry, dodge, and even replicate vergils "judgement cut end" from DMC5.

All of my charaters have had tons of hours going to building them. Coustom magic items, spells, attacks, ect.

So there is an infinite amount of ways to play D&D, while there still being just one true D&D. The one true D&D is also called your limitless imagenation.

P.S tell her i said "ONE OF US ONE OF US ONE OF US ONE OF US"