This post originally appeared in an edition of What’s the Difference?, a weekly newsletter for the curious and confused by New York City writer Brette Warshaw. Eater will be publishing all editions that parse food-related differences, though those hardly scratch the surface of the world’s (and the newsletter’s) curiosities: Sign up to get What’s the Difference? in your inbox or catch up on the full archive.

What’s the difference between...

Seltzer, Club Soda, and Sparkling Mineral Water?

We all love our Pellegrino and LaCroix and the various fancy and non-fancy bubbly waters in between, but what are we actually drinking? Turns out there are marked differences in the various waters con gas we have available to us in these glorious times.

Let’s start with the most basic: seltzer. Seltzer is just plain ol’ water, carbonated with added carbon dioxide. This is the bubbly stuff that’s most likely to come flavored, since it’s such a neutral canvas; it’s the base for your LaCroix and those less-delicious Poland Spring flavored guys you get at the bodega.

Club soda is also carbonated with carbon dioxide, but unlike seltzer, it has the addition of potassium bicarbonate and potassium sulfate in the water. These minerals give it a slightly saltier taste than seltzer, which makes it a favorite of bartenders for mixed drinks.

Sparkling mineral water is made with natural spring or well water, which means it has naturally occurring minerals (like salts and sulphur compounds) in it. These minerals sometimes give the water a natural carbonation; other times, carbon dioxide is added for extra oomph. Depending on where the water’s from, it might taste heavier than seltzer or club soda — or you may just detect some sort of presence of taste, unlike its more-tasteless brethren.

• What’s the Difference Between Seltzer, Club Soda, and Sparkling Mineral Water? [wtd]