Who is a public figure
People who aren't public figures can create a user page that has the format "Users/username".
Public figures can have a user page, but in addition there is a public figure page that has the format "First Last" with any appropriate initials as well.
You can edit your user page to your hearts content, but the public figure page is a public page.
If you want to add something or respond to something placed on the public figure page you can use the /Talk page, or edit the page and be respectful of other editors.