The first two elements of the Fibonacci series are 0 and 1, respectively. We can calculate the third element of the series by adding the preceding two elements and will get the third term as 0 + 1, which is equal to 1. Similarly, the fourth term will be the sum of the second and third terms, which is 1 + 1 = 2 and so on. The series of such numbers is known as a Fibonacci Series.