what are pimentos
Pimentos are small, sweet, mild red peppers, often called pimiento or cherry peppers, and they’re usually much gentler than spicy chiles.
What they are
They’re a type of chili pepper in the Capsicum annuum family, typically heart-shaped or roundish, with a bright red color when ripe. They’re commonly used stuffed into olives, blended into pimento cheese, or dried and ground into paprika.
Taste and heat
Pimentos taste sweet and juicy, with very little heat, usually around 100–500 Scoville Heat Units. That makes them one of the mildest peppers people commonly eat.
Simple example
A familiar example is the red piece inside a green olive; that’s often pimento.
TL;DR: pimentos are mild, sweet red peppers best known from olives and pimento cheese.