I wonder if I bought a book out of Barnes and Noble Web site or Web site if Sony would be able to read on my Kindle? Anyone know?

I want an electronic book, but I can decide between the corner and plug in your opinion is the best?

I’m leaning on the Kindle, but I wanted some reviews! My mother said I could get either for my birthday and I did more research on the Kindle, and so far I would have liked what I read! But I also head that improves the Nook, and I always see in Barnes and Noble. What? Thank you.