This information is being used to create a config.php file.
If for any reason this automatic file creation does not work, do not worry. All this does is fill in the database information to a configuration file.
you may also simply open config-sample.php in a text editor, fill in your information, and save it as config.php.
In all likelihood, these items were supplied to you by your web host. If you do not have this information, then you will need to contact them before you can continue. If you are ready...