When you add the previous number to the current one to get the next number in a sequence, starting with 1. Sorry if that's a bit hard to understand; it works better with an example:
the first number is 1. Add it to the previous number (assumed to be 0) to get 1 again. So so far the sequence goes 1,1. Then 1+1=2, the next number in the sequence, so you get 1,1,2 etc.etc. until you get up to 1,1,2,3,5,8...
it starts with 0, 1....and then follows Xn = Xn-1 + Xn-2
current no. is sum of previous 2 like
The Fibonacci sequence is named after Leonardo of Pisa, who was known as Fibonacci.
The Fibonacci numbers are studied as part of number theory and have applications in the counting of mathematical objects such as sets, permutations and sequences and to computer science.
Fibonacci sequence= 1, 1, 2, 3, 5, 8,...
You just add up the two previous numbers.
You could use it if you're referring to the golden ratio.
Google it, and you'll find tons of information about it!