Hi, SS
It is not a dumb question, and I will try my best to explain. I am sure someone will come along who will do better.
So, the answer is yes and no. Did that help.
No, because Sony does not read the Kindle format. Kindle does not read the Sony ePub.
Yes, because there are ways to get a Kindle book to the Sony, if you are willing to do a bit of stuff.
I have not done this as I have quite a few books to read already.
I guess, I am suppose to say, "Google is your friend" as we are not suppose to give directions on "how" to do that. It may be or it may not be legal in the country where you live.
I would sure like to get some of the Kindle freebies that don"t show up on the other sites. I wish everyone would use smashwords, too.