What is a blog, is it like Facebook?

I am starting my first blog conversation with the topic, "What is a blog, is it like Facebook?"  Well, the answer is no.  On Facebook we talk about how our day at work was and where we are going tomorrow or who made us mad today.  People respond back.....  It is basically a chit, chat conversation back and forth with any of our friends who happen to be online or be checking their smartphones at the time.  Don't get me wrong, I love that daily banter as much as the next person but that is not what a blog is.  A blog has more substance to it.  It is about a topic that is clearly defined and then a definition is given or a perhaps a discussion about that topic such as how to do something or how to get to a particular place.  Regardless, a blog has a clearly defined topic in which the writer has written about.  Then readers can post comments about it, if they choose to, and a discussion can ensue about the topic.  Either way, it is a way for the writer to share their thoughts or information with the readers.