BIM, if not Building information modelling is a concept that came in to existence in 1970 which involves generating and managing a digital representation of a building. In other words, this whole concept is about creating a virtual building inside a computer and using it to extract information such as light analysis, geographic information, quantities, cost estimates, and properties of building components. material tracking and ordering etc.
Autodesk Revit and Graphicsoft ArchiCAD are among the leading software packages which are widely used in BIM. Proficiency in Revit Architecture or Archicad are highly regarded by employers in Building design industry.