Basic Concept Of Real Numbers

Natural Numbers (N)- All positive numbers starting form one. e.g 1,2,3,4.........                                  

Whole Numbers  (W)- All positive numbers starting form zero. e.g 0,1,2.3,4..........

Integers(I or Z) - All positive and negative natural numbers including zero.
                             e.g ......3,2,1,0,1,2,3,.........  

Even Natural Numbers(E)-The natural numbers which are divisible by 2  e.g 2,4,6,8,.........

Odd Natural Numbers(O)-The natural numbers which are not divisible by 2 e.g 1,3,5,7,...........

Prime Numbers(P)-A natural number which is greater then 1 and divisible by 1 and by itself only.
                                e.g  2,3,5,7,11,13....................

Composite Numbers(C)-A natural number which greater then 1 and is not prime.
                                         e.g 4,6,8,9..............

Co-Prime Numbers-If two numbers do not have any factor (other then 1) common e.g 6 and 25.

Rational Numbers(Q)-A number ,which can be expressed in the form p/q . and q should not be zero
                                     e.g 1/2, 3/2 .......

Irrational Numbers(Q Bar)-Non terminating and non-repeating numbers
                                             e.g .101001000100001.......

Real Numbers(R)- Rational and Irrational numbers,taken together