There are five types of noun:
-- Vyaktivachak- Which are proper (eg: Taj Mahal, Delhi, Sachin Tendulkar etc..)
--Jaativachak- Which are common and does not have a proper name (eg: Peacock, Mountains, Book etc..
--Bhavvachak- Which are abstract (eg: happy, sad, crying etc..
--Dravyavachak- Which includes materials (eg: copper, gold, silver etc)
-- Samudayvachak or Samuhvachak- which is a group (eg: Sena, Kaksha, Sabha etc..)