What does IDK stand for?

IDK stand for I Don't Know.
IDK-IDK stand for I Don't Know.

  What does IDK mean? 

The full form of IDK is I don know which is used to say that anyone does not have any sort of information and awareness regarding.

For example, I ask someone that where is Balawaristan located the person doesn't know about Balawaristan then he or she will reply that I don't know.