Free blog always comes with certain limitations. While you create blog at free blogging platform such as blogger, wordpress, blogspot, you get a sub domain, not your own. You may not have full control over your blog and you may not be able to customize it. You cannot use your own domain name or premium themes you wish to install. You will have limited diskspace and you might see adds in your free blog. If you need fully featured blog, you should consider self hosted WordPress blog.