Some times you don't need the overhead of creating an object with state.
In these cases, a module can be used.
A module is very similar to a class (in fact, Module is Classes parent in the object hierarchy) - the main difference being that rather than using instance methods, we use class methods.
Class methods start with self. and are directly called on a module.
For example:
module Speaker
def self.echo(something)
"#{something} ... #{something}"
end
end
Speaker.echo("Hello") #=> "Hello ... Hello"