Question: what is the difference between seltzer and hard seltzer?
Answer: At its most basic level, hard seltzer is seltzer with alcohol in it. What that alcohol is made out of can differ — usually it's just fermented cane sugar with added fruit flavors, but sometimes, like other “flavored malt beverages” such as Bud Light's Lime-A-Ritas, it uses malted barley.