An idea is the central thought or meaning expressed in a short sentence or phrase with no executional details

Anatomy of an idea consists of:

• Focused centrality.
• Conceptual, with no executional details.
• Precise and to the point.
• Short, single sentence.

Example for 1-line idea:

• A personal, portable device that washes, cleanses your face.
• Water-free facewash for using out of home.

On the other hand, a concept is more detail oriented. It is an explanatory brief used to explain the idea with multiple benefits, reasons-to-believe, price, positioning and visual cues.

Example of a concept:

• XYZ Hotels brings to you all the renowned comfort without the worry of having to settle the bill at the time of checkout. You can pay your bills in 3 easy instalments after you check out. This scheme is available for all our club members. No more worries about your credit card limits or cash.
• PQR is ready with X Series its new foldable, fluid phone. It can be folded into as small a size as memory chip and slip inside your wallet. It can also expand to become the size of an entire TV screen, allowing you to enjoy the latest streaming content on your phone with the big screen experience. PQR X Series – a whole new world.