The New panel contains the building blocks you can use to build your website. Until now, it has lived in the toolbar at the top of your website.
In the image below, you can see the label “New” which you can use to open the New panel. You can also see the File panel icon highlighted, which opened a slidebar on the left.
The File panel has been turned into a general purpose Sidebar, containing both the File panel and the New panel as you can see in the image below.
You will find separate Local and Installed sections as you can see on the image below.
The Installed section at the bottom lists all your installed packages. These are read-only, meaning you can drag elements from them onto your page, but you can’t customize them there.
The Local section at the top lists your custom instances. This is your writable area, where you can add anything, customize them, sort them, group them.
If you often find yourself dragging an element from the Installed section to your page, only to make the same changes, you should copy the customized element to your Local section, so you don’t have to apply the same changes again and again.