To ISBN or not to ISBN

You have a finshed book, be it a novel, a novella, a compilation of shorties, or maybe it's a cookbook; and now you want to self publish.  You read through each websites requirements, or should I say skim then you come to the question about ISBN.  Scratching your head you decide to Google it but this leads to more confusion. 

This blog is going to give you answer in what an ISBN is, and the different types. The legal ramifications of how you choose to get your ISBN. And how to avoid these ramifications.