Wikipedia:Tutorial (Namespaces)
In addition to the articles and their Talk pages, there are some other categories of behind-the-scenes pages that help Wikipedians communicate with each other, and serve a variety of other roles in building Wikipedia.
User pages and User Talk pages
If you want to share information about yourself, the place to put it is your User page. You can only access your User page if you are logged in as a registered user.
If other users want to communicate with you, they will leave a message on your User Talk page a
Some other areas
These different areas are often referred to with the label "namespace", as in the User namespace. These include the Project namespace (also called the Wikipedia namespace) that provides information about Wikipedia and how to use it, and the MediaWiki namespace which contains interface texts such as link labels and messages. All the pages in both these areas also have corresponding Talk pages.
Content written in a template page will be displayed in articles that contain the corresponding tag. For example, the content written in Template:Protected will appear in any article that contains the {{protected}} tag. Take a look at Wikipedia:Template messages to see what templates have already been created. You can use the corresponding tags. You can create new templates.
For more details, see Wikipedia:Namespace.
Continue with the tutorial.