In order to use Blogger, you created an account with a user name and password, and a display name. This information is associated with any blog that you create. If you like, you can offer more information about yourself to the people who read your blog. This information is called your Blogger profile.
Of course, how much you tell is completely up to you. You can remain strictly anonymous, or you can give your real name, your location, a description of yourself, your birthdate, and more. Or you can find some compromise between the two extremes. In addition, detailing your interests, favorite books, music, and movies can help you find other bloggers with similar interests.
All the information you choose to share is displayed on your Blogger profile page. You can also have a subset of your profile appear right on your blog along with a link to the full profile page. Either way, the amount of information you share is always up to you.