A red herring is a term used to describe something that distracts attention from the main issue or topic. It's an idiomatic expression derived from the use of smoked fish, which was often used in the past as a training device for dogs. The trainers would drag a "red herring" across a trail to throw off the scent and confuse the dog during training exercises. In modern usage, the phrase is commonly used to describe something that diverts attention away from what's really important or relevant in a discussion or situation.