Classification of Universe

The universe may be classified either on the basis of number of units and on the basis   of existence of units as is clear from the following chart :

(1)   Finite or Definite Universe: A finite universe is one in which the   number of items us determinable for example number of students in Rajasthan university in2002, the    population of India in 2001 etc.

(2)   Infinite or Indefinite Inverse: As  infinite inverse is that in which  the number of items cannot be determined or the universe is so large that for all practical purposed it is regarded as infinite, for example number of stars in the sky, number of leaves on a tree, number of fish in the ocean etc.

(3)   Real or True Existence Universe: If all the units or elements of the  universe are true  and inexistence, such inverse  is called real inverse, for example number of income tax assesses, number  of works in a mill, number of hospital  in India etc.

(4)   Hypothetical or Theoretical Universe:  Where units of the universe are not in existence and we can  only imagine them, is called   theoretical or  hypothetical universe for example throwing of dice to get six, number of times a coin falling with head upward or with tail upward  on tossing the coin etc.