Collections are containers or virtual folders used to collect and organize content. You can put every kind of file in a collection, including other collections. You can create as many collections as you want and they can be placed in any folder in Elvis, just like all other files. A folder structure can be useful to organize your collections.
A collection can have metadata of its own (tags, status, description etc.) and because of this collections can be found using the search engine. Adding names and other metadata can be a useful way to quickly find collections and the files contained inside them.
To add items to a collection, you need to make the collection active. Active collections show up in the right sidebar. You can drag 'n drop files to these active collections. Collections in the folder browser are created in the selected folder. Collections created in the sidebar are automatically created in your own private user zone, but you can always move them between zones to make them visible to other users. Note that the content in the collection will only be visible to people with (at least view) access to those files.