Definition & Meaning of "the cat's whiskers"

What is the origin of the idiom "the cat's whiskers" and when to use it?

During the vibrant Jazz Age of the 1920s in the United States, the idiom "the cat's whiskers" came into existence. This lighthearted and imaginative expression captures the essence of being remarkably fashionable, stylish, or exceptional. It thrived in an era defined by the rise of flappers and a burgeoning youth culture, symbolizing an affinity for avant-garde trends and a desire to be at the forefront of sophistication and novelty.