Please note that MS Word uses built-in styles for text formatting. To get these styles, you need to use style name using local language e.g. if you are working with German document and want to use Heading 1 style, you need to use style name 'Überschrift 1'.
The names of built-in styles in MS Word are localized for different languages. Using a style identifier you can find the correct style regardless of the document language.
These are two different styles. To check these styles properties, please open MS Word and check these styles in style pane.