Type of numbers

Natural Numbers: Counting 1,2,3,4,5... are called natural numbers.

Whole Numbers: All counting numbers together with zero are whole numbers. So 0 is only a whole number which is not a natural number

Integers: All counting numbers, 0 and negative number together form the set of integers.
i.e. [....,-2,-1,0,1,2,.....] are integers.

Prime numbers: A number greater than 1 is called a prime number if it has exactly two factors, namely 1 and the number itself.

Composite numbers: Numbers greater than 1 which are not prime are called composite numbers.

Co-primes: Two numbers are said to be co primes if their H.C.F is 1. example: (2,3),(8,11) etc