The Panorama web interface now displays the preferred releases and the corresponding base releases of PAN-OS software. Before you upgrade or downgrade Panorama or PAN-OS, you can view the list of preferred and base releases and choose your preferred target PAN-OS release. Preferred releases offer the latest and the most advanced features and ensure stability and performance. When there are no preferred releases available, the corresponding base version is not displayed. If necessary, you can choose to view either preferred releases or base releases.