Convex vs concave payoff

Some bets have small downside and huge upside. Some have small upside and huge downside. Spot which shape you are in.

Definition

A framing of decisions by the shape of their payoff curve, where convex payoffs have asymmetric upside from small inputs and concave payoffs have asymmetric downside.

Step 1

Predict first

In one or two sentences, what do you think this concept means? Wrong is fine; the small struggle is what makes the answer stick.