<p>For a person without a comp-sci background, what is a lambda in the world of Computer Science?</p>

It refers to
lambda calculus
, which is a formal system that just has lambda expressions, which represent a function that takes a function for its sole argument and returns a function. All functions in the lambda calculus are of that type, i.e.,
```
λ : λ → λ
```
.
Lisp used the lambda concept to name its anonymous function literals. This lambda represents a function that takes two arguments, x and y, and returns their product:
```
```
(lambda (x y) (* x y))
```
```
It can be applied in-line like this (evaluates to
50
):
```
```
((lambda (x y) (* x y)) 5 10)
```
```