You see they have a way to put carbon dioxide into the drink liquid. It makes for a nice drinking experience. There are many brands of these drinks available. Some of these brands are well over a hundred years old. Perhaps you have heard of a Coca Cola, for instance.
What other brands do you like? Waterloo is my favorite of the cheap seltzers, it's got the best bubbles. Nothing I've had beats topo Chico tho (glass only, can and plastic do something that ruins the bubbles) but it's like 5x the price so I can never actually recommend it to people