Hosting is a service that relies on disk space (server) lease from the chosen vendor. This is the place where Your website files are stored. Users can access Your website through domain, which is Your website adress. Every vendor provides all necessary tools to go through configuration process.
Totally free and the most powerfull Content Management System based on PHP and MySQL available in many languages. Download it from the Internet and upload to Your web server. After installation You’ll be ready to make default site looks fabulous, just by upload purchased theme via WP Control Panel.