The header is the part of your site that contains the logo and navigation. In responsive sites, there are three types of headers available when creating responsive sites. These types are fixed, flexible and sticky headers.
By default headers in Responsive are fixed. This means that the header contains the logo and navigation, but is locked and will not be customizable by adding elements from the Add Elements section.
Headers can be set to be flexible by turning the header into a row. By doing this, the header can act like a row that can take in elements from the Add Elements section. For more information on turning the header into a row, click here.
Please keep in mind that if you have turned your header into a flexible row and later decide that you want your header to be fixed, unfortunately, changing the header back would not be possible.
Sticky headers are available as an experimental feature. When a header is set to be a sticky header, this means that as pages are scrolled, the header will remain in its fixed position at the top of the page as the page is being scrolled. In addition, sticky headers can be flexible.