What is malt?

No joke: I am not kidding you when I say last week I got a milkshake, thought aloud “I really wish they had malt, it would’ve been even better”. My husband ask “what is malt anyways?”. I said “I actually have no idea, let me google it.” I found the answer (although it wasn’t particularly satisfying) and told him what I found out and topped it off with “I wish Adam had a video on it”. And slightly more than a week later, here we are. Truly amazing.