Explanation of small Redis snippet
===

I'm referring to this [great answer](http://stackoverflow.com/a/10140190/806374) given by @Sripathi Krishnan to the question asked here on SO: Is Redis just a cache

I'm trying to learn how to use redis and my research brought me to the question on SO.

Can someone please explain the reason for these two lines in the code because I'm still finding it difficult to understand their usefulness in the code Sripathi gave in the answer.  

    $ HINCRBY unique_ids question 1
    $ HINCRBY unique_ids answer 1  

I know that it creates a hash with 'unique_ids' as its key with fields 'question' and  'answer' first initialised to 0 then increased to 1. Apart from this, I don't see any link of the unique_ids key with the flow but I'm not sure if my noob mind is missing something.