Transparent Header allows you to easily create beautiful and attractive headers. Enabling this option will set your primary header background to transparent and pull the page content to the top. It will merge the primary header and the page content. That means your top part of the page content will be set as a background to the transparent header.
It is a premium feature available with Suki Pro. You can activate the module from Appearance > Suki > Transparent Header.
You can find the settings under Appearance > Customize > Header > Transparent Header. This setting is global default setting for transparent header.
If you want to override transparent header global default setting on each different page type (posts archive page, single post page, search or 404 page), please go to page settings. You can also override the transparent header setting (enable/disable transparent header) on each post/page using page settings metabox in post/page editor.