What are lambda functions

Lambda functions are small, anonymous functions defined using the `lambda` keyword in programming languages like Python. They are used for short, throwaway functions that are not required to be named. Lambda functions can have any number of arguments but only one expression, which is evaluated and returned. They are often used for functional programming tasks, such as passing a simple function as an argument to higher-order functions. 

Example in Python:

```python

add = lambda x, y: x + y

print(add(3, 5))  # Output: 8

```