So, is seltzer water and sparkling water the same thing? Yes, with asterisks. They’re both fizzy water, but seltzer is the generic version, and sparkling water is the brand-name version with a better marketing team. It’s like asking if a “sandwich” and a “sub” are the same—technically yes, but one sounds cooler.
My advice: buy whatever is on sale, because water is water, and bubbles are bubbles. The only real enemy is the stuff that comes out of your tap at 2 a.m., which is ironically called “water” but tastes like a swimming pool. That is not the same as anything.
Now go forth and fizz, my confused friend. And if someone at a party corrects you on the difference, just pour your seltzer on their ice cream and walk away. They’ll thank you later—after they learn to chill out about bubbles.