What does .between? method means in Ruby? -

I have a school practice and I can not solve it. Can you help me? The problem is:

Try using a method that takes two arguments - use the middle? The method of determining whether the number is between 2 and 1.

I tried to know that .between? What is the method? I know this is a method

method, and you can use it like this:

  2.between? (1, 3) # = & gt; True