  In this short article, we overview a concept of electronic toroidal
multipoles, and their ordering with associated physical properties in
non-magnetic and magnetic materials. The toroidal multipoles are introduced as
microscopic electronic variables in view of symmetry and connection to Dirac
theory. They are classified according to crystallographic and magnetic point
groups, which allows us to discuss various possible cross correlations in a
transparent and unified manner. The representative examples of toroidal orders
and related phenomena, and the mutual relationship between these orders are
given, with focusing on monopoles and dipoles. The concept of toroidal
multipoles would promote future studies toward observations and identifications
of unknown electronic phases and their related physical phenomena.
