The "Header Only" is a sub-part of all "Typical Page Contents" so you can define your Header styles there. Hoewever sometimes you will need only a header. In that case you can use  "Header Only"

Type: Here you will find all default header styles (H1 - H5) and probably some variants that are specific to your Website

Alignmet:  You can set it to left, center or right

Date:  If set it will be rendered above the header (not implemented)

Link: you can link the header to a page

Subheader: The Subheader position might be below or above the header, it depends on the layout of your Website

Header 1

Header 2

with sub header

Header 3

with sub header

Header 3 with link

with sub header

Header 3 centered

with sub header

Header 3 right