The heap analyzer receives information about segments from four OpenVMS
  memory managers that perform allocations and deallocations in memory
  space.  Each memory manager has a slightly different view, or overall
  picture, of dynamic memory.

  Each memory manager recognizes a different set of segment types.  This
  means that, within the heap analyzer, where views from the memory
  managers are layered on each other, a single memory location can be
  associated with one or more segment types.

  The left window of the Views-and-Types Display contains a hierarchy
  that reflects this integration:

   -  Views (integrates all four views)

   -  Blocks (block view from LIB$VM memory manager)

   -  Images (image view from SYS$IMAGE memory manager)

   -  Regions (system services view from SYS$SERVICES memory manager)

   -  Zones (zone view from LIB$VM_ZONE memory manager)

  To see the individual segment types recognized by each memory manager,
  expand the default display by double clicking MB1 on Blocks, Images,
  Regions, or Zones keywords.  To collapse an individual listing, click
  MB3 on the keyword you previously selected.

  This hierarchy offers you the following choices in scope:

   -  To affect all segment types in all views:

      Click MB1 on the Views keyword

   -  To affect all segment types in one view:

      Click MB1 on the Blocks, Images, or Zones keywords.

   -  To affect individual segment types:

      Double click MB1 on the view of your choice, and click MB1 on one
      or more single segment types.