The Structure of a Library
The general structure of an Aspect library consists of two main parts. The first part is responsible for the physical organization of the files on disk, while the second part offers additional organization possibilities that work independently of where photos are stored.
Physical organization
The physical organization part of the library consists of events and individual photos, which are visible through the photo stream. Events can be thought as a kind of automatically organized folder. They have a name and can contain arbitrary files and sub folders, but in contrast to ordinary folders, they are automatically organized into year folders or other kinds of folder structures (see the “Libraries in the File System” chapter for more information).
Individual photos on the other hand are distributed up into separate folders — one folder per year by default. Individual photo folders do not have an associated name and are not visible as individual folders within the application. Instead the contained photos are all displayed within the photo stream as a long list of photos.
Virtual organization
On top of the physical file organization, there are several tools to set up additional organization systems. These “virtual” structures are stored either within the library catalog, or in the form of metadata that is associated with each photo.
Organization structures stored within the library catalog include collections and saved searches, while keywords are stored as XMP metadata.