A numerical sequence is a list of numbers arranged in a specific order according to a particular rule or pattern. Each number in the sequence is called a term, and the position of each term is usually indicated by its index. For example, in the sequence 2, 4, 6, 8, each term increases by 2, demonstrating a simple arithmetic pattern. Numerical sequences can be finite, having a limited number of terms, or infinite, continuing indefinitely. They can also follow various rules, such as Fibonacci sequences, where each term is the sum of the two preceding ones. Understanding these sequences is essential in fields like mathematics and computer science.