At Joomla templates section, click on any of the Voyager templates to access the template's configuration page and you should see some of the template's settings, your focus here is the layout. In the demo site, you can actually test these layouts and how they look like on the frontend. Essentially the layout setting will affect the placements of modules in EasyBlog's post entry page.
Alternate Module - Allow placement of modules in one column on the left and one column on the right.
Single Module Left - Allow placement of modules in one column on the left.
Single Module Right - Allow placement of modules in one column on the right.
Double Module Left - Allow placement of modules in two columns on the left.
Double Module Right - Allow placement of modules in two columns on the right.
None - No module positions available on the left and right columns.
From Joomla templates section, you may notice that there are several other Voyager templates on the list with different names. They are actually the same, except for the name and layout configuration. For example, the template with the name Voyager - Single Module Right will have its default layout set to Single Module Right.
This is to provide convenience to site admins if they want to have different layouts for different menu items. All they have to do is assign the respective template to the desired menu in the Menu Assignment section.