What is the difference between girder and beam?

Basically beam and girder , both are horizontal and are subjected to flexural loads ( bending moment and shears )Beam is having a rectangular shape where as girder is normally having " I " shape cross section.Beam is usually in RCC whereas Girder is in structural steel.Beam is a short span member ( upto5 m ) whereas girder is long span member.Beam is used in context with a residential building whereas girder is used in Industrial roofs or in bridges.Some types of beams are never used in girder. for example , we shall never see : hidden-girder ( like hidden beam ) or Inverted girder ( like inverted beams ).