What type of sequence is defined by a constant difference between terms?

The correct answer is an arithmetic sequence, which is defined by having a constant difference between consecutive terms. In an arithmetic sequence, you can take any two successive terms and find that the difference between them remains the same throughout the sequence. This consistent difference is known as the common difference.

For example, consider the sequence 2, 5, 8, 11, where the common difference is 3 (5 - 2, 8 - 5, and 11 - 8 all equal 3). This property of maintaining a fixed difference sets arithmetic sequences apart from other types of sequences.

In contrast, a geometric sequence involves multiplying by a constant ratio between terms rather than adding a constant difference. A Fibonacci sequence is characterized by each term being the sum of the two preceding terms, creating a unique pattern that doesn't maintain a constant difference. Lastly, a quadratic sequence is defined by the second differences of its terms being constant, but the first differences can decrease or increase, which does not meet the criteria for a constant difference. Thus, the defining characteristic of an arithmetic sequence is a constant difference, validating the choice of this answer.