The params of add options page -- explain in detail

add_options_page( string $page_title,  string $menu_title,  string $capability, string $menu_slug,  callable $function = '' )

Parameters #Parameters

$page_title

(string) (Required) The text to be displayed in the title tags of the page when the menu is selected. It will be displayed in the position 1.

$menu_title

(string) (Required) The text to be used for the menu.  It will be displayed in the position 2.

$capability

(string) (Required) The capability required for this menu to be displayed to the user.

This confused me because I don't know what capabilities I can choose until I found this page: List of possible capabilities are here. 

$menu_slug

(string) (Required) The slug name to refer to this menu by (should be unique for this menu). This will be used in the url. For example: http://127.0.0.1/html2/wp-admin/options-general.php?page=baidu-translator. 'baidu-translator' is a menu_slug.

$function

(callable) (Optional) The function to be called to output the content for this page.

Default value: ''.