Why a blog?!
A blog is like a personal diary. An online diary on which you can express your feelings, ideas and thoughts, so that other people can know you better.
You can join communities with people that have the same interest as you, same ideas, same hobbies and you can exchange oppinions. It’s easier than creating a website using a html code for example. For this you must have strong knowledge about the html code. Also, it's cheaper, you don’t have to buy programs like Dreamweaver or Web Page Maker.
An alternative for building a site are platforms for creating blogs, such as WordPress, Blogspot or Joomla.
You have total control on your blog. You can decide who can comment and who not; you can delete offensive things. You can post pictures, videos or you can even promote your friends, who also own a blog.