/*!

\page grouping_elements_page Grouping elements

In Mesh module it is possible to create groups of mesh elements:
nodes, edges, faces or volumes. One group contains elements of only
one type. The following ways of creation are possible:

- by selecting the elements using filters and/or directly on the 
  presentation in the VTK viewer, and/or by using elements of other
  mesh objects - \ref standalone_group "Standalone group"
  tab of \ref creating_groups_page "Create group" dialog.
- by creating a group of elements generated on the chosen geometrical
  object - \ref group_on_geom "Group on geometry" tab of
  \subpage creating_groups_page "Create group" dialog and
  \subpage create_groups_from_geometry_page "Create Groups from Geometry"
  dialog.
- by creating a group of elements satisfying to certain criteria -
  \ref group_on_filter "Group on filter" tab of
  \subpage creating_groups_page "Create group" dialog.
- by creating groups of nodes and elements from the chosen submesh
  (type of elements depends on dimension of submesh geometry) -
  using <b>Mesh -> Construct Group</b> menu item (available in context
  menu as well).
- by creating groups of entities from existing groups of superior
  dimensions - using \subpage group_of_underlying_elements_page
  "Create Group of Underlying Elements" dialog.

The created groups can be later:

- \subpage editing_groups_page "Edited"
- \subpage using_operations_on_groups_page "Subjected to Boolean operations"
- \subpage deleting_groups_page "Deleted"

An important tool, providing filters for creation of \b Standalone
groups is \ref selection_filter_library_page.

*/