Introduction:
The Fibonacci sequence is a set of numbers that starts with 0 and 1, and each subsequent number in the sequence is the sum of the previous two. This sequence is named after Leonardo Fibonacci, an Italian mathematician who introduced it to the Western world in his book Liber Abaci.

Explanation:
The Fibonacci sequence is a mathematical concept that has many real-world applications. It has been used in fields like architecture, music, and even in the stock market. The sequence can be represented as: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, and so on.

Formula:
The formula to calculate the nth number in the Fibonacci sequence is:

F(n) = F(n-1) + F(n-2)

Where F(n) represents the nth number in the sequence, and F(n-1) and F(n-2) represent the two preceding numbers in the sequence.

Real World Applications:
The Fibonacci sequence has many real-world applications. Some of them are:

1. Architecture - The sequence has been used in the design of buildings, such as the Guggenheim Museum in New York.

2. Music - The sequence has been used in the rhythm of music, such as in the works of composer Bartók.

3. Stock Market - The sequence has been used in predicting stock market trends.

Conclusion:
In conclusion, the Fibonacci sequence is a fascinating mathematical concept that has many real-world applications. It is a simple yet powerful sequence that has captured the imagination of mathematicians, scientists, and artists for centuries. Understanding the sequence can help us better understand the world around us and appreciate the beauty of mathematics.