The Vault is used to store designs, technology files, library data and other items in a managed way. Vault Virtual Folders are used to present these items in a meaningful way.
Using Vault Virtual Folders
Folders in the Vault work in a very similar way to the Folders you are already used to using on your computer. An item in the Vault can only belong to one Folder. They do not actually have to belong to any Folder, in which case they will be displayed at the top most level of the tree view in the Browser tree view, although for ease of use it is recommended that all items are assigned to a folder.
The dialogs used to check items into the Vault will guide you towards using Folders, helping you to keep things organised.