When you use Google Buzz, you have to create a Google profile page.
Your profile is the way you present yourself on Google products and across the web. With your profile, you can manage the information--such as your bio, contact details, and links to other sites about you or created by you--that people see.
At a minimum, your first name, last name, and photo will be public on the Internet. You can then provide a variety of additional information about yourself in your profile. You can also enable people to contact you without displaying your contact information.
It allows you to control how you appear on Google and tell others a bit more about who you are. With a Google profile, you can easily share your web content on one central location. You can include, for example, links to your blog, online photos, and other profiles such as Facebook, LinkedIn, and more. You have control over what others see. Your profile won't display any private information unless you've explicitly added it.
You can also allow people to find you more easily by enabling your profile to be searched by your name. Simply set your existing profile to show your full name publicly.
If you've been writing reviews on Google Maps, creating articles on Google Knol, sharing Google Reader items, or adding books to your Google Book Search library, you may already have a profile. See and customize your profile.
(example & text ©Google)
More informations about your profile, its privacy & security and many more topics in the Profiles pages of the Google Accounts Help. It's all about Editing, customizing, adding links, photos, location but also its URL, its access security or how to report inappropriate content.