Arithmetic Sequence: In an arithmetic sequence, each term after the first is found by adding the same number to the previous term. This number is called the common difference. The general form of an arithmetic sequence is an = a1 + (n - 1)d, where an is the n-th term, a1 is the first term, and d is the common difference.
Geometric Sequence: In a geometric sequence, each term after the first is found by multiplying the previous term by the same number. This number is called the common ratio. The general form of a geometric sequence is an = a1 * r^(n-1), where an is the n-th term, a1 is the first term, and r is the common ratio.
Fibonacci Sequence: The Fibonacci sequence is a series of numbers in which each number is the sum of the two preceding ones, usually starting with 0 and 1. The sequence begins 0, 1, 1, 2, 3, 5, 8, 13, and so on.