WordPress comes in two versions.
1) The WordPress blog site provides free individual blogs for personal and limited business use. These have limited features and, although excellent for basic hobby or business blogs they are not recommended for serious bloggers who wish to seriously monetize their blog site or who are building a full website for information distribution or product/service sales or launches. The WordPress blog site, shown below, can be accessed at http://wordpress.com/.
2) The WordPress content management system (CMS) software is downloadable from http://wordpress.org/, shown below, and is the package to use for self-hosted stand-alone blogs and websites. This is your best choice for basic blogs to elaborate websites where you want to be fully in control. This package is also free and offers an extensive array of free and paid plugins, themes, and other features and third party services from a variety of sources.