Toybox Champions, the Swizzle Works card battler, plus plain definitions of the two genres people confuse it with.
One game lives here: Toybox Champions. Toys duel on a bedroom floor. You play a card, spend Imagination, summon a toy, and take the enemy hero to zero. The web version is free, with no ads and no purchases.
Two guides sit next to it. One explains what a collectible card game is, the other what a deck building game is. Toybox gets called both and is neither, so the guides say what each genre means and where this game lands.
The blog post walks through a first session. If you have ten minutes and a browser, that is the place to start.