Is lambda a type of higher order function?

I saw this question on one of the job postings and its asking what's a lambda function and what its relation to higher order function. I already know how to use lambda function but not quite confident explaining it so I did a little googling and found this: What is a lambda (function)? and this http://en.wikipedia.org/wiki/Higher-order_function

The definition of HOF which says should at least take one or more function or return a function fits on what a lambda is, so my question is.. is a lambda a type of HOF?

Or anyone who could explain their relation further?