Working with Views > ECAD Viewables > About Placed and Unplaced Components
  
About Placed and Unplaced Components
A PCB layout design consists of placed and unplaced components. A placed component appears in the graphics area. The component can have a position and orientation in the design, or it can be placed outside the board outline or at an arbitrary point, to be positioned later.
An unplaced component exists in the design database, and has all the connectivity and attributes of a placed component, but it has not been instantiated in the design with a component symbol. Unplaced components do not appear in the graphics area, but they are in the Components partition of the substructure pane. You can select unplaced components, and they are included in a BOM or a Design Statistics report.
Deleted components are components that no longer exist in the PCB layout database.