If you don’t wish to worry about hosting and related stuff at all then simply choose the WordPress.com option. It will simply create a blog. You’re allowed to choose a unique domain, but it comes with ‘wordpress.com’ extension.
If you are creating this first blog or may be test one just to start off your blogging career or just to share your knowledge with all your readers, then this option is perfect. You don’t need to worry about having any technical knowledge neither you need to worry about any security or performance issues.
It’s all taken care of automatically. It will be started once you sign up for an account which is just like any other popular social platform. Once done with sign up process, you can choose a domain there and free option (don’t go for paid version unless you’re sure of them, although they may be off your interest) and that’s it. Your first blog is setup and live.
You can login within Dashboard area to manage certain things about and can use this blog to share whatever knowledge you wish every of your follower should be aware of.
On other hand, if you’re good at technical part then go for self-hosted WordPress blog. You need to have a good hosting provider for that. Many popular hosts provides a standard cPanel which offers one-click install tools like SimpleScripts using which the whole WordPress script can be installed and activated automatically (by simply following certain on screen instructions).
You need to pay for hosting and also buy a domain with any TLD (.com, .net, .org, etc.) of your choice. Once setup is done, login with your credentials and start setting up around. You need to have a lot of technical knowledge to get used to of the options you’ll see in there. Although there are various WordPress tutorials available over YouTube and various other blogs over internet (including ours) who can help you get all the knowledge needed. But still you have to be an expert in most common things which will take a lot of practices.
So, WordPress.com is simple but it doesn’t provide freedom of changing even the most common settings rather it simply provides a platform to share knowledge. On other side, self-hosted option provides every freedom with all the features first option provides but requires technical knowledge and you can’t expect it to come without any cost.