The Components tab in the Organiser contains a set of Component Galleries containing components for you to use in your publication. It also provides a place for you to store resources you may want to use repeatedly.
Using the Component menu at the top of the Opus Editor you can do many things, including opening, closing and renaming galleries as well creating your own galleries and consolidating resources in the galleries.
If you don’t want to create your own gallery, then Opus provides a Scratch Pad gallery. The Scratch Pad is a special temporary gallery where you can store things while you work on your publication. Anything in this gallery will be lost when you close your publication.