A Lambda Expression is a concise way to represent an anonymous function in programming. It allows developers to create small, single-use functions without formally defining them with a name. Lambda expressions are commonly used in languages like Python, Java, and JavaScript to simplify code, especially when working with functions that take other functions as arguments. These expressions can take any number of parameters but can only have one expression. They are particularly useful in functional programming and for operations like filtering, mapping, or reducing collections. By using lambda expressions, programmers can write cleaner and more readable code, enhancing productivity and maintainability.