What is the origin of the idiom "line of least resistance" and when to use it?

The idiom "line of least resistance" is derived from the principles of fluid dynamics and physics. It is based on the observation that in the natural world, fluids like water and air tend to follow the path that offers the least resistance to their flow. This concept is known as the "path of least resistance" and has been applied metaphorically to describe the easiest or most straightforward way to accomplish something with minimal effort or confrontation.