At its essence, a concept topic answers the question, "What is...?". Concept topics provide contextual information that is needed to understand a product or system functionality as a whole.

Conceptual topics help readers tie their existing knowledge to a new product or task. If you provide instructions for "Installing the OS-XT29", your reader might wonder what the OS-XT29 is, how it differs from other versions, what it does, and more. Concept topics provide those missing pieces of information.

This concept is used as an introduction for a toaster manual:

Classic Toaster Introduction

The Classic Toaster™ is the one-of-a-kind, classic breakfast machine you wanted since you were old enough to eat solid food. Have perfect slices of delight with your favorite jam or butter. Easily achieve exquisitely toasted bagels with a push of a button.

Classic Toaster