Basic principle and Overture

Basic principle noun - Principles from which other truths can be derived.

Overture and basic principle are semantically related. in introduction topic. In some cases you can use "Overture" instead a noun phrase "Basic principle", when it comes to topics like something new.

Overture noun - A performance, activity, or event that precedes and sets the stage for the main event.

Basic principle and overture are semantically related. Sometimes you can replace phrase "Basic principle" with "Overture", this terms are similar.