English idioms are phrases or expressions that have a figurative meaning that is different from their literal meaning. They are often used in casual conversation and can add color and depth to language. For example, "break a leg" is an idiom that means "good luck" in the context of a performance or presentation, even though the literal meaning of the phrase is quite different. Idioms can be challenging to understand for non-native speakers or those who are unfamiliar with them, as their meanings are often not immediately obvious. However, they are an important part of English language and culture, and mastering them can help improve communication skills and cultural understanding.