What is the origin of the idiom "light as a feather" and when to use it?

The origin of the idiom "light as a feather" is rooted in the physical properties of feathers, which are known for their lightness and delicate nature. This phrase is used metaphorically to describe something that is extremely light or weightless, emphasizing its lack of heaviness. Feathers, being lightweight and often associated with flight and freedom, serve as a fitting comparison to convey a sense of lightness and ease.