How to do Paragraph Styles?

I’m looking around in Engraver mode after finishing my first project.
I’ve manually add the field Subtitle with the {@flowSubtitle@} tag (it was not in the dropdownbox). That works for me. I can change the font height etc.

Now I see there is an menu-item Engraver - Paragraph styles. Here I can add the Subtitle, changing the size, font etc also.

Is there an difference between both? What is preferred?

The nice thing about using a dedicated paragraph style is that you can change it everywhere it’s used in your project simply by editing the style in the dialog, rather than having to go and find all of the place you’ve overridden the appearance of the text in another paragraph style and fix it up.