A folder is a container that you can use to group any managed resources in whatever manner makes sense for your environment; for example, you might create a folder for each branch office in your organization. Folders can contain any type of resource from anywhere in your XenServer environment. Resources can be accessed independently of the folder in which they are referenced.
The organization of folders in XenCenter is conceptual, not physical. The resources are not physically located in the folder, therefore, you can place resources into folders independently of their physical location. For example, placing a VM into a folder does not place its host server in the folder as well; placing a server into a folder does not place all the VMs and storage resources on that server into the folder as well.
Folders can also be used in search queries, for example, you can search by folder, with a contained in / not contained in relation and a drop down hierarchy of folders. See Create a Search Query.
The folder in which a resource is currently located is shown on the resource's General tab and in its Properties dialog box, so you can see folder information for a resource at all times. You can also move a resource into a different folder or remove it from a folder from the General tab.
The simplest way to create a new folder is through Resources pane. Click Organization Views in the Navigation pane, and then select Objects by Folder. In the Resources pane, click on the Folders group, right-click, and select New Folder from the shortcut menu. Type a name for the new folder, select the server where your folder metadata will be stored, and then click Create.
You can also create new folders from the General tab for any resource:
The simplest way to move a resource into a folder is by dragging it from within the Resources pane or from the Search tab and dropping it onto the folder. Resources can only be in one folder, so if the resource is already in another folder it will be moved when you drag and drop in onto a different folder.
You can also move a resource into a different folder or remove it from a folder from the General tab:
Note that you won't actually delete the resources in the folder when you delete the folder: they will be returned to the general collection.