The platform is the software you use to set up your website. Unless you speak HTML (the high level language all websites are written in) and don’t plan to learn it (I have neither the time nor the patience) you need a platform.
There are many platforms. I don’t know which are good or bad so… I got WordPress (http://www.wordpress.com ). Where did I get it? You guessed it, I got it as Managed WordPress on Godaddy ( http://www.godaddy.com) when I got my Domain name and Web Host. Bundled again. A few dollars more a month.