A mathematical sequence is a list of numbers arranged in a specific order, following a particular rule. Each number in the sequence is called a term, and the position of each term is important. For example, in the sequence 2, 4, 6, 8, each number increases by 2, making it an arithmetic sequence. Sequences can also be more complex, like the Fibonacci sequence, where each term is the sum of the two preceding ones, starting with 0 and 1. This creates a pattern like 0, 1, 1, 2, 3, 5, 8. Understanding sequences helps in various fields, including computer science and finance.