The Delegate Space feature is used to define hierarchies. A space property defined in a delagate space is inherited to the delegating space. Also homepages for doctypes, not defined in the delegating space will be inherited from the next delegate space.
A space attached to the Search Space of a space enables macros selecting documents (for instance the Display Table Macro) to automatically include documents from the search space.
Delegate spaces help to organize information that is used by more than one space. Resources may be delegated to other spaces. This includes the definition of space properties and providing homepages for documents of a given type.